Re: Multinode Cassandra and sstableloader
From Michael Laing - posted on the wrong thread : We use Alain's solution as well to make major operational revisions. We have a red team and a blue team in each AWS region, so we just add and drop datacenters to get where we want to be. Pretty simple. 2015-03-31 15:50 GMT+02:00 Alain RODRIGUEZ arodr...@gmail.com: IMHO, the most straight forward solution is to add cluster2 as a new DC for mykeyspace and then drop the old DC. That's how we migrated to VPC (AWS) and we love this approach since you don't have to mess with your existing cluster, plus sync is made automatically and you can then drop your old DC safely, when you are sure. I put steps on this ML long time ago: https://mail-archives.apache.org/mod_mbox/incubator-cassandra-user/201406.mbox/%3cca+vsrlopop7th8nx20aoz3as75g2jrjm3ryx119deklynhq...@mail.gmail.com%3E Also Datastax docs: https://www.datastax.com/documentation/cassandra/2.0/cassandra/operations/ops_add_dc_to_cluster_t.html get data from cluster1, put it to cluster2 wipe cluster1 I would definitely use this method to do this (I actually did already, multiple times). Up to you, I heard once that there is almost as much way of doing operational on Cassandra as the number of operators :). You should go with method you can be confident with. I can assure the one I propose is quite secure. C*heers, Alain 2015-03-31 15:32 GMT+02:00 Serega Sheypak serega.shey...@gmail.com: I have to ask you if you considered doing an Alter keyspace, change RF The idea is dead simple: get data from cluster1, put it to cluster2 vipe cluster1 I understand drawbacks of streaming sstableloader approach, I need right now something easy. Later we consider switch to Priam since it does backup/restore in a right way. 2015-03-31 14:45 GMT+02:00 Alain RODRIGUEZ arodr...@gmail.com: Hi, Despite of I understand that it's not the best solution, I need it for testing purposes, I have to ask you if you considered doing an Alter keyspace, change RF 1 for mykeyspace on cluster2 and nodetool rebuild to add a new DC (your cluster2) ? In the case you go your way (sstableloader) also advice you to make a snapshot (instead of just flushing) to avoid fails due to compactions on your active cluster1. To answer your question, sstableloader is supposed to distribute correctly data on the new cluster depending on your RF and topology. Basically if you run sstable loader just on sstable c1.node1 my guess is that you will have all the data present on c1.node1 stored on the new c2 (each data to corresponding node). So if you have an RF=3 on c1, you should have all the data on c2 just by running sstableloader from c1.node1, if you are using RF=1 on c1, then you need to load data from c1.each_node. I suppose that cluster2.nodeXXX doesn't matter and act as a coordinator. I never used the tool, but that's what would be logical imho. Wait for a confirmation as I wouldn't to lead you to a failure of any kind. Also, I don't know if data is also replicated directly with sstableloader or if you need to repair c2 after loading data. C*heers, Alain 2015-03-31 13:21 GMT+02:00 Serega Sheypak serega.shey...@gmail.com: Hi, I have a simple question and can't find related info in docs. I have cluster1 with 3 nodes and cluster2 with 5 nodes. I want to transfer whole keyspace named 'mykeyspace' data from cluster1 to cluster2 using sstableloader. I understand that it's not the best solution, I need it for testing purposes. What I'm going to do: 1. Recreate keyspace schema on cluster2 using schema from cluster1 2. nodetool flush for mykeyspace.source_table being exported from cluster1 to cluster2 3. Run sstableloader for each table on cluster1.node01 sstableloader -d cluster2.nodeXXX.com /var/lib/cassandra/data/mykeyspace/source_table-83f369e0d6e511e4b3a6010e8d2b68af/ What should I get as a result on cluster2? *ALL* data from source_table? or Just data stored in *partition of source_table* I'm confused. Doc says I just run this command to export table from cluster1 to cluster2, but I specify path to a part of source_table data, since other parts of table should be on other nodes.
Testing sstableloader between Cassandra 2.1 DSE and community edition 2.1
Hi, I have 2 cassandra clusters. cluster1 is datastax community 2.1 cluster2 is datastax DSE I can run sstableloader from cluster1(Community) and stream data to cluster2 (DSE) But I get exception while streaming from cluster2 (DSE) to cluster1 (Community) The expection is: Could not retrieve endpoint ranges: java.lang.NullPointerException java.lang.RuntimeException: Could not retrieve endpoint ranges: at org.apache.cassandra.tools.BulkLoader$ExternalClient.init(BulkLoader.java:282) at org.apache.cassandra.io.sstable.SSTableLoader.stream(SSTableLoader.java:149) at org.apache.cassandra.tools.BulkLoader.main(BulkLoader.java:94) Caused by: java.lang.NullPointerException at org.apache.cassandra.serializers.BooleanSerializer.deserialize(BooleanSerializer.java:33) at org.apache.cassandra.serializers.BooleanSerializer.deserialize(BooleanSerializer.java:24) at org.apache.cassandra.db.marshal.AbstractType.compose(AbstractType.java:142) at org.apache.cassandra.cql3.UntypedResultSet$Row.getBoolean(UntypedResultSet.java:102) at org.apache.cassandra.config.CFMetaData.fromSchemaNoColumnsNoTriggers(CFMetaData.java:1701) at org.apache.cassandra.config.CFMetaData.fromThriftCqlRow(CFMetaData.java:1059) at org.apache.cassandra.tools.BulkLoader$ExternalClient.init(BulkLoader.java:274)
Re: SSTable structure
Hi bharat, you are talking about Cassandra 1.2.5 Does it fit Cassandra 2.1? Were there any significant changes to SSTable format and layout? Thank you, article is interesting. Hi jacob jacob.rho...@me.com, HBase does it for example. http://hbase.apache.org/book.html#_hfile_format_2 It would be great to give general ideas. It could help to understand schema design problems. You start to understand better how Cassandra scans data how you can utilize its power. 2015-04-01 5:39 GMT+02:00 Bharatendra Boddu bharatend...@gmail.com: Some time back I created a blog article about the SSTable storage format with some code references. Cassandra: SSTable Storage Format http://distributeddatastore.blogspot.com/2013/08/cassandra-sstable-storage-format.html - bharat On Mon, Mar 30, 2015 at 5:24 PM, Jacob Rhoden jacob.rho...@me.com wrote: Yes updating code and documentation can sometimes be annoying, you would only ever maintain both if it were important. It comes down or is having the format of the data files documented for everyone to understand an important thing? __ Sent from iPhone On 31 Mar 2015, at 11:07 am, daemeon reiydelle daeme...@gmail.com wrote: why? Then there are 2 places 2 maintain or get jira'ed for a discrepancy. On Mar 30, 2015 4:46 PM, Robert Coli rc...@eventbrite.com wrote: On Mon, Mar 30, 2015 at 1:38 AM, Pierre pierredev...@gmail.com wrote: Does anyone know if there is a more complete and up to date documentation about the sstable files structure (data, index, stats etc.) than this one : http://wiki.apache.org/cassandra/ArchitectureSSTable No, there isn't. Unfortunately you will have to read the source. I'm looking for a full specification, with schema of the structure if possible. It would be nice if such fundamental things were documented, wouldn't it? =Rob
Re: Testing sstableloader between Cassandra 2.1 DSE and community edition 2.1
Sorry cluster1 community version is: ii cassandra 2.1.3 distributed storage system for structured data cluster2 DSE version is: ii dse-libcassandra4.6.2-1 The DataStax Enterprise package includes a production-certifie 2015-04-01 14:53 GMT+02:00 Serega Sheypak serega.shey...@gmail.com: Hi, I have 2 cassandra clusters. cluster1 is datastax community 2.1 cluster2 is datastax DSE I can run sstableloader from cluster1(Community) and stream data to cluster2 (DSE) But I get exception while streaming from cluster2 (DSE) to cluster1 (Community) The expection is: Could not retrieve endpoint ranges: java.lang.NullPointerException java.lang.RuntimeException: Could not retrieve endpoint ranges: at org.apache.cassandra.tools.BulkLoader$ExternalClient.init(BulkLoader.java:282) at org.apache.cassandra.io.sstable.SSTableLoader.stream(SSTableLoader.java:149) at org.apache.cassandra.tools.BulkLoader.main(BulkLoader.java:94) Caused by: java.lang.NullPointerException at org.apache.cassandra.serializers.BooleanSerializer.deserialize(BooleanSerializer.java:33) at org.apache.cassandra.serializers.BooleanSerializer.deserialize(BooleanSerializer.java:24) at org.apache.cassandra.db.marshal.AbstractType.compose(AbstractType.java:142) at org.apache.cassandra.cql3.UntypedResultSet$Row.getBoolean(UntypedResultSet.java:102) at org.apache.cassandra.config.CFMetaData.fromSchemaNoColumnsNoTriggers(CFMetaData.java:1701) at org.apache.cassandra.config.CFMetaData.fromThriftCqlRow(CFMetaData.java:1059) at org.apache.cassandra.tools.BulkLoader$ExternalClient.init(BulkLoader.java:274)
[SECURITY ANNOUNCEMENT] CVE-2015-0225
CVE-2015-0225: Apache Cassandra remote execution of arbitrary code Severity: Important Vendor: The Apache Software Foundation Versions Affected: Cassandra 1.2.0 to 1.2.19 Cassandra 2.0.0 to 2.0.13 Cassandra 2.1.0 to 2.1.3 Description: Under its default configuration, Cassandra binds an unauthenticated JMX/RMI interface to all network interfaces. As RMI is an API for the transport and remote execution of serialized Java, anyone with access to this interface can execute arbitrary code as the running user. Mitigation: 1.2.x has reached EOL, so users of = 1.2.x are recommended to upgrade to a supported version of Cassandra, or manually configure encryption and authentication of JMX, (seehttps://wiki.apache.org/cassandra/JmxSecurity). 2.0.x users should upgrade to 2.0.14 2.1.x users should upgrade to 2.1.4 Alternately, users of any version not wishing to upgrade can reconfigure JMX/RMI to enable encryption and authentication according to https://wiki.apache.org/cassandra/JmxSecurityor http://docs.oracle.com/javase/7/docs/technotes/guides/management/agent.html Credit: This issue was discovered by Georgi Geshev of MWR InfoSecurity
Frequent timeout issues
Hi, I am new to Cassandra. I have setup a cluster with Cassandra 2.0.13. I am writing the same data in HBase and Cassandra and find that the writes are extremely slow in Cassandra and frequently seeing exception “Cassandra timeout during write query at consistency ONE. The cluster size for both HBase and Cassandra are same. Looks like something is wrong with my cluster setup. What can be the possible issue? Data and commit logs are written into two separate disks. Regards, Amlan
Re: Frequent timeout issues
Amlan, Can you provide information on how much data is being written? Are any of the columns really large? Are any writes succeeding or are all timing out? Regards, Eric R Medley On Apr 1, 2015, at 9:03 AM, Amlan Roy amlan@cleartrip.com wrote: Hi, I am new to Cassandra. I have setup a cluster with Cassandra 2.0.13. I am writing the same data in HBase and Cassandra and find that the writes are extremely slow in Cassandra and frequently seeing exception “Cassandra timeout during write query at consistency ONE. The cluster size for both HBase and Cassandra are same. Looks like something is wrong with my cluster setup. What can be the possible issue? Data and commit logs are written into two separate disks. Regards, Amlan
Datastax driver object mapper and union field
Hi!
We need to implement a union field in our cassandra data model and we're
using the datastax Mapper. Anyone have any recommendations for doing
this? I'm thinking something like:
public class Value {
int dataType;
String valueAsString;
double valueAsDouble;
}
If the Value is a String, do we need to store a double as well (and vice
versa)? Or should we convert the double to a java.lang.Double and null
it? If we did the latter, do we have to worry about tombstones?
Thanks and appreciate any advice!
Cheers,
Craig
Re: Frequent timeout issues
Also, can you provide the table details and the consistency level you are using? Regards, Eric R Medley On Apr 1, 2015, at 9:13 AM, Eric R Medley emed...@xylocore.com wrote: Amlan, Can you provide information on how much data is being written? Are any of the columns really large? Are any writes succeeding or are all timing out? Regards, Eric R Medley On Apr 1, 2015, at 9:03 AM, Amlan Roy amlan@cleartrip.com mailto:amlan@cleartrip.com wrote: Hi, I am new to Cassandra. I have setup a cluster with Cassandra 2.0.13. I am writing the same data in HBase and Cassandra and find that the writes are extremely slow in Cassandra and frequently seeing exception “Cassandra timeout during write query at consistency ONE. The cluster size for both HBase and Cassandra are same. Looks like something is wrong with my cluster setup. What can be the possible issue? Data and commit logs are written into two separate disks. Regards, Amlan
Re: Frequent timeout issues
Hi Eric, Thanks for the reply. Some columns are big but I see the issue even when I stop storing the big columns. Some of the writes are timing out, not all. Where can I find the number of writes to Cassandra? Regards, Amlan On 01-Apr-2015, at 7:43 pm, Eric R Medley emed...@xylocore.com wrote: Amlan, Can you provide information on how much data is being written? Are any of the columns really large? Are any writes succeeding or are all timing out? Regards, Eric R Medley On Apr 1, 2015, at 9:03 AM, Amlan Roy amlan@cleartrip.com wrote: Hi, I am new to Cassandra. I have setup a cluster with Cassandra 2.0.13. I am writing the same data in HBase and Cassandra and find that the writes are extremely slow in Cassandra and frequently seeing exception “Cassandra timeout during write query at consistency ONE. The cluster size for both HBase and Cassandra are same. Looks like something is wrong with my cluster setup. What can be the possible issue? Data and commit logs are written into two separate disks. Regards, Amlan
Table design for historical data
Hi, My requirement is to design a table for historical state information (not exactly time-series). For ex: I have devices connecting and disconnecting to the management platform. I want to know the details such as (name, mac, os, image, etc.) for all devices connected to the management platform in a given interval (start and end time). Any help on table design for this use-case? Regards, Firdousi
Re: Frequent timeout issues
Did not see any exception in cassandra.log and system.log. Monitored using
JConsole. Did not see anything wrong. Do I need to see any specific info? Doing
almost 1000 writes/sec.
HBase and Cassandra are running on different clusters. For cassandra I have 6
nodes with 64GB RAM(Heap is at default setting) and 32 cores.
On 01-Apr-2015, at 8:43 pm, Eric R Medley emed...@xylocore.com wrote:
Are you seeing any exceptions in the cassandra logs? What are the loads on
your servers? Have you monitored the performance of those servers? How many
writes are you performing at a time? How many writes per seconds?
Regards,
Eric R Medley
On Apr 1, 2015, at 9:40 AM, Amlan Roy amlan@cleartrip.com wrote:
Write consistency level is ONE.
This is the describe output for one of the tables.
CREATE TABLE event_data (
event text,
week text,
bucket int,
date timestamp,
unique text,
adt int,
age listint,
arrival listtimestamp,
bank text,
bf double,
cabin text,
card text,
carrier listtext,
cb double,
channel text,
chd int,
company text,
cookie text,
coupon listtext,
depart listtimestamp,
dest listtext,
device text,
dis double,
domain text,
duration bigint,
emi int,
expressway boolean,
flight listtext,
freq_flyer listtext,
host text,
host_ip text,
inf int,
instance text,
insurance text,
intl boolean,
itinerary text,
journey text,
meal_pref listtext,
mkp double,
name listtext,
origin listtext,
pax_type listtext,
payment text,
pref_carrier listtext,
referrer text,
result_cnt int,
search text,
src text,
src_ip text,
stops int,
supplier listtext,
tags listtext,
total double,
trip text,
user text,
user_agent text,
PRIMARY KEY ((event, week, bucket), date, unique)
) WITH CLUSTERING ORDER BY (date DESC, unique ASC) AND
bloom_filter_fp_chance=0.01 AND
caching='KEYS_ONLY' AND
comment='' AND
dclocal_read_repair_chance=0.10 AND
gc_grace_seconds=864000 AND
index_interval=128 AND
read_repair_chance=0.00 AND
replicate_on_write='true' AND
populate_io_cache_on_flush='false' AND
default_time_to_live=0 AND
speculative_retry='99.0PERCENTILE' AND
memtable_flush_period_in_ms=0 AND
compaction={'class': 'SizeTieredCompactionStrategy'} AND
compression={'sstable_compression': 'LZ4Compressor’};
On 01-Apr-2015, at 8:00 pm, Eric R Medley emed...@xylocore.com wrote:
Also, can you provide the table details and the consistency level you are
using?
Regards,
Eric R Medley
On Apr 1, 2015, at 9:13 AM, Eric R Medley emed...@xylocore.com wrote:
Amlan,
Can you provide information on how much data is being written? Are any of
the columns really large? Are any writes succeeding or are all timing out?
Regards,
Eric R Medley
On Apr 1, 2015, at 9:03 AM, Amlan Roy amlan@cleartrip.com wrote:
Hi,
I am new to Cassandra. I have setup a cluster with Cassandra 2.0.13. I am
writing the same data in HBase and Cassandra and find that the writes are
extremely slow in Cassandra and frequently seeing exception “Cassandra
timeout during write query at consistency ONE. The cluster size for both
HBase and Cassandra are same.
Looks like something is wrong with my cluster setup. What can be the
possible issue? Data and commit logs are written into two separate disks.
Regards,
Amlan
Re: Frequent timeout issues
Using the datastax driver without batch.
http://www.datastax.com/documentation/developer/java-driver/2.1/java-driver/whatsNew2.html
On 01-Apr-2015, at 9:15 pm, Brian O'Neill b...@alumni.brown.edu wrote:
Are you using the storm-cassandra-cql driver?
(https://github.com/hmsonline/storm-cassandra-cql)
If so, what version?
Batching or no batching?
-brian
---
Brian O'Neill
Chief Technology Officer
Health Market Science, a LexisNexis Company
215.588.6024 Mobile • @boneill42
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From: Amlan Roy amlan@cleartrip.com
Reply-To: user@cassandra.apache.org
Date: Wednesday, April 1, 2015 at 11:37 AM
To: user@cassandra.apache.org
Subject: Re: Frequent timeout issues
Replication factor is 2.
CREATE KEYSPACE ct_keyspace WITH replication = {
'class': 'NetworkTopologyStrategy',
'DC1': '2'
};
Inserts are happening from Storm using java driver. Using prepared statement
without batch.
On 01-Apr-2015, at 8:42 pm, Brice Dutheil brice.duth...@gmail.com wrote:
And the keyspace? What is the replication factor.
Also how are the inserts done?
On Wednesday, April 1, 2015, Amlan Roy amlan@cleartrip.com wrote:
Write consistency level is ONE.
This is the describe output for one of the tables.
CREATE TABLE event_data (
event text,
week text,
bucket int,
date timestamp,
unique text,
adt int,
age listint,
arrival listtimestamp,
bank text,
bf double,
cabin text,
card text,
carrier listtext,
cb double,
channel text,
chd int,
company text,
cookie text,
coupon listtext,
depart listtimestamp,
dest listtext,
device text,
dis double,
domain text,
duration bigint,
emi int,
expressway boolean,
flight listtext,
freq_flyer listtext,
host text,
host_ip text,
inf int,
instance text,
insurance text,
intl boolean,
itinerary text,
journey text,
meal_pref listtext,
mkp double,
name listtext,
origin listtext,
pax_type listtext,
payment text,
pref_carrier listtext,
referrer text,
result_cnt int,
search text,
src text,
src_ip text,
stops int,
supplier listtext,
tags listtext,
total double,
trip text,
user text,
user_agent text,
PRIMARY KEY ((event, week, bucket), date, unique)
) WITH CLUSTERING ORDER BY (date DESC, unique ASC) AND
bloom_filter_fp_chance=0.01 AND
caching='KEYS_ONLY' AND
comment='' AND
dclocal_read_repair_chance=0.10 AND
gc_grace_seconds=864000 AND
index_interval=128 AND
read_repair_chance=0.00 AND
replicate_on_write='true' AND
populate_io_cache_on_flush='false' AND
default_time_to_live=0 AND
speculative_retry='99.0PERCENTILE' AND
memtable_flush_period_in_ms=0 AND
compaction={'class': 'SizeTieredCompactionStrategy'} AND
compression={'sstable_compression': 'LZ4Compressor’};
On 01-Apr-2015, at 8:00 pm, Eric R Medley emed...@xylocore.com wrote:
Also, can you provide the table details and the consistency level you are
using?
Regards,
Eric R Medley
On Apr 1, 2015, at 9:13 AM, Eric R Medley emed...@xylocore.com wrote:
Amlan,
Can you provide information on how much data is being written? Are any of
the columns really large? Are any writes succeeding or are all timing out?
Regards,
Eric R Medley
On Apr 1, 2015, at 9:03 AM, Amlan Roy amlan@cleartrip.com wrote:
Hi,
I am new to Cassandra. I have setup a cluster with Cassandra 2.0.13. I
am writing the same data in HBase and Cassandra and find that the writes
are extremely slow in Cassandra and frequently seeing exception
“Cassandra timeout during write query at consistency ONE. The cluster
size for both HBase and Cassandra are same.
Looks like something is wrong with my cluster setup. What can be the
possible issue? Data and commit logs are written into two separate
disks.
Regards,
Amlan
--
Brice
Re: Frequent timeout issues
Are HBase and Cassandra running on the same servers? Are the writes to each of
these databases happening at the same time?
Regards,
Eric R Medley
On Apr 1, 2015, at 10:12 AM, Brice Dutheil brice.duth...@gmail.com wrote:
And the keyspace? What is the replication factor.
Also how are the inserts done?
On Wednesday, April 1, 2015, Amlan Roy amlan@cleartrip.com
mailto:amlan@cleartrip.com wrote:
Write consistency level is ONE.
This is the describe output for one of the tables.
CREATE TABLE event_data (
event text,
week text,
bucket int,
date timestamp,
unique text,
adt int,
age listint,
arrival listtimestamp,
bank text,
bf double,
cabin text,
card text,
carrier listtext,
cb double,
channel text,
chd int,
company text,
cookie text,
coupon listtext,
depart listtimestamp,
dest listtext,
device text,
dis double,
domain text,
duration bigint,
emi int,
expressway boolean,
flight listtext,
freq_flyer listtext,
host text,
host_ip text,
inf int,
instance text,
insurance text,
intl boolean,
itinerary text,
journey text,
meal_pref listtext,
mkp double,
name listtext,
origin listtext,
pax_type listtext,
payment text,
pref_carrier listtext,
referrer text,
result_cnt int,
search text,
src text,
src_ip text,
stops int,
supplier listtext,
tags listtext,
total double,
trip text,
user text,
user_agent text,
PRIMARY KEY ((event, week, bucket), date, unique)
) WITH CLUSTERING ORDER BY (date DESC, unique ASC) AND
bloom_filter_fp_chance=0.01 AND
caching='KEYS_ONLY' AND
comment='' AND
dclocal_read_repair_chance=0.10 AND
gc_grace_seconds=864000 AND
index_interval=128 AND
read_repair_chance=0.00 AND
replicate_on_write='true' AND
populate_io_cache_on_flush='false' AND
default_time_to_live=0 AND
speculative_retry='99.0PERCENTILE' AND
memtable_flush_period_in_ms=0 AND
compaction={'class': 'SizeTieredCompactionStrategy'} AND
compression={'sstable_compression': 'LZ4Compressor’};
On 01-Apr-2015, at 8:00 pm, Eric R Medley emed...@xylocore.com
javascript:_e(%7B%7D,'cvml','emed...@xylocore.com'); wrote:
Also, can you provide the table details and the consistency level you are
using?
Regards,
Eric R Medley
On Apr 1, 2015, at 9:13 AM, Eric R Medley emed...@xylocore.com
javascript:_e(%7B%7D,'cvml','emed...@xylocore.com'); wrote:
Amlan,
Can you provide information on how much data is being written? Are any of
the columns really large? Are any writes succeeding or are all timing out?
Regards,
Eric R Medley
On Apr 1, 2015, at 9:03 AM, Amlan Roy amlan@cleartrip.com
javascript:_e(%7B%7D,'cvml','amlan@cleartrip.com'); wrote:
Hi,
I am new to Cassandra. I have setup a cluster with Cassandra 2.0.13. I am
writing the same data in HBase and Cassandra and find that the writes are
extremely slow in Cassandra and frequently seeing exception “Cassandra
timeout during write query at consistency ONE. The cluster size for both
HBase and Cassandra are same.
Looks like something is wrong with my cluster setup. What can be the
possible issue? Data and commit logs are written into two separate disks.
Regards,
Amlan
--
Brice
Re: Frequent timeout issues
Replication factor is 2.
CREATE KEYSPACE ct_keyspace WITH replication = {
'class': 'NetworkTopologyStrategy',
'DC1': '2'
};
Inserts are happening from Storm using java driver. Using prepared statement
without batch.
On 01-Apr-2015, at 8:42 pm, Brice Dutheil brice.duth...@gmail.com wrote:
And the keyspace? What is the replication factor.
Also how are the inserts done?
On Wednesday, April 1, 2015, Amlan Roy amlan@cleartrip.com wrote:
Write consistency level is ONE.
This is the describe output for one of the tables.
CREATE TABLE event_data (
event text,
week text,
bucket int,
date timestamp,
unique text,
adt int,
age listint,
arrival listtimestamp,
bank text,
bf double,
cabin text,
card text,
carrier listtext,
cb double,
channel text,
chd int,
company text,
cookie text,
coupon listtext,
depart listtimestamp,
dest listtext,
device text,
dis double,
domain text,
duration bigint,
emi int,
expressway boolean,
flight listtext,
freq_flyer listtext,
host text,
host_ip text,
inf int,
instance text,
insurance text,
intl boolean,
itinerary text,
journey text,
meal_pref listtext,
mkp double,
name listtext,
origin listtext,
pax_type listtext,
payment text,
pref_carrier listtext,
referrer text,
result_cnt int,
search text,
src text,
src_ip text,
stops int,
supplier listtext,
tags listtext,
total double,
trip text,
user text,
user_agent text,
PRIMARY KEY ((event, week, bucket), date, unique)
) WITH CLUSTERING ORDER BY (date DESC, unique ASC) AND
bloom_filter_fp_chance=0.01 AND
caching='KEYS_ONLY' AND
comment='' AND
dclocal_read_repair_chance=0.10 AND
gc_grace_seconds=864000 AND
index_interval=128 AND
read_repair_chance=0.00 AND
replicate_on_write='true' AND
populate_io_cache_on_flush='false' AND
default_time_to_live=0 AND
speculative_retry='99.0PERCENTILE' AND
memtable_flush_period_in_ms=0 AND
compaction={'class': 'SizeTieredCompactionStrategy'} AND
compression={'sstable_compression': 'LZ4Compressor’};
On 01-Apr-2015, at 8:00 pm, Eric R Medley emed...@xylocore.com wrote:
Also, can you provide the table details and the consistency level you are
using?
Regards,
Eric R Medley
On Apr 1, 2015, at 9:13 AM, Eric R Medley emed...@xylocore.com wrote:
Amlan,
Can you provide information on how much data is being written? Are any of
the columns really large? Are any writes succeeding or are all timing out?
Regards,
Eric R Medley
On Apr 1, 2015, at 9:03 AM, Amlan Roy amlan@cleartrip.com wrote:
Hi,
I am new to Cassandra. I have setup a cluster with Cassandra 2.0.13. I am
writing the same data in HBase and Cassandra and find that the writes are
extremely slow in Cassandra and frequently seeing exception “Cassandra
timeout during write query at consistency ONE. The cluster size for both
HBase and Cassandra are same.
Looks like something is wrong with my cluster setup. What can be the
possible issue? Data and commit logs are written into two separate disks.
Regards,
Amlan
--
Brice
Re: Frequent timeout issues
And the keyspace? What is the replication factor.
Also how are the inserts done?
On Wednesday, April 1, 2015, Amlan Roy amlan@cleartrip.com wrote:
Write consistency level is ONE.
This is the describe output for one of the tables.
CREATE TABLE event_data (
event text,
week text,
bucket int,
date timestamp,
unique text,
adt int,
age listint,
arrival listtimestamp,
bank text,
bf double,
cabin text,
card text,
carrier listtext,
cb double,
channel text,
chd int,
company text,
cookie text,
coupon listtext,
depart listtimestamp,
dest listtext,
device text,
dis double,
domain text,
duration bigint,
emi int,
expressway boolean,
flight listtext,
freq_flyer listtext,
host text,
host_ip text,
inf int,
instance text,
insurance text,
intl boolean,
itinerary text,
journey text,
meal_pref listtext,
mkp double,
name listtext,
origin listtext,
pax_type listtext,
payment text,
pref_carrier listtext,
referrer text,
result_cnt int,
search text,
src text,
src_ip text,
stops int,
supplier listtext,
tags listtext,
total double,
trip text,
user text,
user_agent text,
PRIMARY KEY ((event, week, bucket), date, unique)
) WITH CLUSTERING ORDER BY (date DESC, unique ASC) AND
bloom_filter_fp_chance=0.01 AND
caching='KEYS_ONLY' AND
comment='' AND
dclocal_read_repair_chance=0.10 AND
gc_grace_seconds=864000 AND
index_interval=128 AND
read_repair_chance=0.00 AND
replicate_on_write='true' AND
populate_io_cache_on_flush='false' AND
default_time_to_live=0 AND
speculative_retry='99.0PERCENTILE' AND
memtable_flush_period_in_ms=0 AND
compaction={'class': 'SizeTieredCompactionStrategy'} AND
compression={'sstable_compression': 'LZ4Compressor’};
On 01-Apr-2015, at 8:00 pm, Eric R Medley emed...@xylocore.com
javascript:_e(%7B%7D,'cvml','emed...@xylocore.com'); wrote:
Also, can you provide the table details and the consistency level you are
using?
Regards,
Eric R Medley
On Apr 1, 2015, at 9:13 AM, Eric R Medley emed...@xylocore.com
javascript:_e(%7B%7D,'cvml','emed...@xylocore.com'); wrote:
Amlan,
Can you provide information on how much data is being written? Are any of
the columns really large? Are any writes succeeding or are all timing out?
Regards,
Eric R Medley
On Apr 1, 2015, at 9:03 AM, Amlan Roy amlan@cleartrip.com
javascript:_e(%7B%7D,'cvml','amlan@cleartrip.com'); wrote:
Hi,
I am new to Cassandra. I have setup a cluster with Cassandra 2.0.13. I am
writing the same data in HBase and Cassandra and find that the writes are
extremely slow in Cassandra and frequently seeing exception “Cassandra
timeout during write query at consistency ONE. The cluster size for both
HBase and Cassandra are same.
Looks like something is wrong with my cluster setup. What can be the
possible issue? Data and commit logs are written into two separate disks.
Regards,
Amlan
--
Brice
Re: Frequent timeout issues
Write consistency level is ONE.
This is the describe output for one of the tables.
CREATE TABLE event_data (
event text,
week text,
bucket int,
date timestamp,
unique text,
adt int,
age listint,
arrival listtimestamp,
bank text,
bf double,
cabin text,
card text,
carrier listtext,
cb double,
channel text,
chd int,
company text,
cookie text,
coupon listtext,
depart listtimestamp,
dest listtext,
device text,
dis double,
domain text,
duration bigint,
emi int,
expressway boolean,
flight listtext,
freq_flyer listtext,
host text,
host_ip text,
inf int,
instance text,
insurance text,
intl boolean,
itinerary text,
journey text,
meal_pref listtext,
mkp double,
name listtext,
origin listtext,
pax_type listtext,
payment text,
pref_carrier listtext,
referrer text,
result_cnt int,
search text,
src text,
src_ip text,
stops int,
supplier listtext,
tags listtext,
total double,
trip text,
user text,
user_agent text,
PRIMARY KEY ((event, week, bucket), date, unique)
) WITH CLUSTERING ORDER BY (date DESC, unique ASC) AND
bloom_filter_fp_chance=0.01 AND
caching='KEYS_ONLY' AND
comment='' AND
dclocal_read_repair_chance=0.10 AND
gc_grace_seconds=864000 AND
index_interval=128 AND
read_repair_chance=0.00 AND
replicate_on_write='true' AND
populate_io_cache_on_flush='false' AND
default_time_to_live=0 AND
speculative_retry='99.0PERCENTILE' AND
memtable_flush_period_in_ms=0 AND
compaction={'class': 'SizeTieredCompactionStrategy'} AND
compression={'sstable_compression': 'LZ4Compressor’};
On 01-Apr-2015, at 8:00 pm, Eric R Medley emed...@xylocore.com wrote:
Also, can you provide the table details and the consistency level you are
using?
Regards,
Eric R Medley
On Apr 1, 2015, at 9:13 AM, Eric R Medley emed...@xylocore.com wrote:
Amlan,
Can you provide information on how much data is being written? Are any of
the columns really large? Are any writes succeeding or are all timing out?
Regards,
Eric R Medley
On Apr 1, 2015, at 9:03 AM, Amlan Roy amlan@cleartrip.com wrote:
Hi,
I am new to Cassandra. I have setup a cluster with Cassandra 2.0.13. I am
writing the same data in HBase and Cassandra and find that the writes are
extremely slow in Cassandra and frequently seeing exception “Cassandra
timeout during write query at consistency ONE. The cluster size for both
HBase and Cassandra are same.
Looks like something is wrong with my cluster setup. What can be the
possible issue? Data and commit logs are written into two separate disks.
Regards,
Amlan
Re: Frequent timeout issues
Are you using the storm-cassandra-cql driver?
(https://github.com/hmsonline/storm-cassandra-cql)
If so, what version?
Batching or no batching?
-brian
---
Brian O'Neill
Chief Technology Officer
Health Market Science, a LexisNexis Company
215.588.6024 Mobile @boneill42 http://www.twitter.com/boneill42
This information transmitted in this email message is for the intended
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copying or other use of, or taking any action in reliance upon, this
information by persons or entities other than the intended recipient is
strictly prohibited.
From: Amlan Roy amlan@cleartrip.com
Reply-To: user@cassandra.apache.org
Date: Wednesday, April 1, 2015 at 11:37 AM
To: user@cassandra.apache.org
Subject: Re: Frequent timeout issues
Replication factor is 2.
CREATE KEYSPACE ct_keyspace WITH replication = {
'class': 'NetworkTopologyStrategy',
'DC1': '2'
};
Inserts are happening from Storm using java driver. Using prepared statement
without batch.
On 01-Apr-2015, at 8:42 pm, Brice Dutheil brice.duth...@gmail.com wrote:
And the keyspace? What is the replication factor.
Also how are the inserts done?
On Wednesday, April 1, 2015, Amlan Roy amlan@cleartrip.com wrote:
Write consistency level is ONE.
This is the describe output for one of the tables.
CREATE TABLE event_data (
event text,
week text,
bucket int,
date timestamp,
unique text,
adt int,
age listint,
arrival listtimestamp,
bank text,
bf double,
cabin text,
card text,
carrier listtext,
cb double,
channel text,
chd int,
company text,
cookie text,
coupon listtext,
depart listtimestamp,
dest listtext,
device text,
dis double,
domain text,
duration bigint,
emi int,
expressway boolean,
flight listtext,
freq_flyer listtext,
host text,
host_ip text,
inf int,
instance text,
insurance text,
intl boolean,
itinerary text,
journey text,
meal_pref listtext,
mkp double,
name listtext,
origin listtext,
pax_type listtext,
payment text,
pref_carrier listtext,
referrer text,
result_cnt int,
search text,
src text,
src_ip text,
stops int,
supplier listtext,
tags listtext,
total double,
trip text,
user text,
user_agent text,
PRIMARY KEY ((event, week, bucket), date, unique)
) WITH CLUSTERING ORDER BY (date DESC, unique ASC) AND
bloom_filter_fp_chance=0.01 AND
caching='KEYS_ONLY' AND
comment='' AND
dclocal_read_repair_chance=0.10 AND
gc_grace_seconds=864000 AND
index_interval=128 AND
read_repair_chance=0.00 AND
replicate_on_write='true' AND
populate_io_cache_on_flush='false' AND
default_time_to_live=0 AND
speculative_retry='99.0PERCENTILE' AND
memtable_flush_period_in_ms=0 AND
compaction={'class': 'SizeTieredCompactionStrategy'} AND
compression={'sstable_compression': 'LZ4Compressor¹};
On 01-Apr-2015, at 8:00 pm, Eric R Medley emed...@xylocore.com
javascript:_e(%7B%7D,'cvml','emed...@xylocore.com'); wrote:
Also, can you provide the table details and the consistency level you are
using?
Regards,
Eric R Medley
On Apr 1, 2015, at 9:13 AM, Eric R Medley emed...@xylocore.com
javascript:_e(%7B%7D,'cvml','emed...@xylocore.com'); wrote:
Amlan,
Can you provide information on how much data is being written? Are any of
the columns really large? Are any writes succeeding or are all timing out?
Regards,
Eric R Medley
On Apr 1, 2015, at 9:03 AM, Amlan Roy amlan@cleartrip.com
javascript:_e(%7B%7D,'cvml','amlan@cleartrip.com'); wrote:
Hi,
I am new to Cassandra. I have setup a cluster with Cassandra 2.0.13. I am
writing the same data in HBase and Cassandra and find that the writes are
extremely slow in Cassandra and frequently seeing exception ³Cassandra
timeout during write query at consistency ONE. The cluster size for both
HBase and Cassandra are same.
Looks like something is wrong with my cluster setup. What can be the
possible issue? Data and commit logs are written into two separate disks.
Regards,
Amlan
--
Brice
replace_address vs add+removenode
Hi. The documentation suggests to use the replace_address startup parameter for replacing a dead node. However, it doesn't motivate why this is superior over adding a new node and retiring the dead one using nodetool removenode. I assume it can be more efficient since the new node can take over the exact tokens of the dead node. Are there any other differences? Can it be reasonable to not use replace_address in the interest of more uniform operations? br, Ulrich
Re: Frequent timeout issues
Are you seeing any exceptions in the cassandra logs? What are the loads on your
servers? Have you monitored the performance of those servers? How many writes
are you performing at a time? How many writes per seconds?
Regards,
Eric R Medley
On Apr 1, 2015, at 9:40 AM, Amlan Roy amlan@cleartrip.com wrote:
Write consistency level is ONE.
This is the describe output for one of the tables.
CREATE TABLE event_data (
event text,
week text,
bucket int,
date timestamp,
unique text,
adt int,
age listint,
arrival listtimestamp,
bank text,
bf double,
cabin text,
card text,
carrier listtext,
cb double,
channel text,
chd int,
company text,
cookie text,
coupon listtext,
depart listtimestamp,
dest listtext,
device text,
dis double,
domain text,
duration bigint,
emi int,
expressway boolean,
flight listtext,
freq_flyer listtext,
host text,
host_ip text,
inf int,
instance text,
insurance text,
intl boolean,
itinerary text,
journey text,
meal_pref listtext,
mkp double,
name listtext,
origin listtext,
pax_type listtext,
payment text,
pref_carrier listtext,
referrer text,
result_cnt int,
search text,
src text,
src_ip text,
stops int,
supplier listtext,
tags listtext,
total double,
trip text,
user text,
user_agent text,
PRIMARY KEY ((event, week, bucket), date, unique)
) WITH CLUSTERING ORDER BY (date DESC, unique ASC) AND
bloom_filter_fp_chance=0.01 AND
caching='KEYS_ONLY' AND
comment='' AND
dclocal_read_repair_chance=0.10 AND
gc_grace_seconds=864000 AND
index_interval=128 AND
read_repair_chance=0.00 AND
replicate_on_write='true' AND
populate_io_cache_on_flush='false' AND
default_time_to_live=0 AND
speculative_retry='99.0PERCENTILE' AND
memtable_flush_period_in_ms=0 AND
compaction={'class': 'SizeTieredCompactionStrategy'} AND
compression={'sstable_compression': 'LZ4Compressor’};
On 01-Apr-2015, at 8:00 pm, Eric R Medley emed...@xylocore.com
mailto:emed...@xylocore.com wrote:
Also, can you provide the table details and the consistency level you are
using?
Regards,
Eric R Medley
On Apr 1, 2015, at 9:13 AM, Eric R Medley emed...@xylocore.com
mailto:emed...@xylocore.com wrote:
Amlan,
Can you provide information on how much data is being written? Are any of
the columns really large? Are any writes succeeding or are all timing out?
Regards,
Eric R Medley
On Apr 1, 2015, at 9:03 AM, Amlan Roy amlan@cleartrip.com
mailto:amlan@cleartrip.com wrote:
Hi,
I am new to Cassandra. I have setup a cluster with Cassandra 2.0.13. I am
writing the same data in HBase and Cassandra and find that the writes are
extremely slow in Cassandra and frequently seeing exception “Cassandra
timeout during write query at consistency ONE. The cluster size for both
HBase and Cassandra are same.
Looks like something is wrong with my cluster setup. What can be the
possible issue? Data and commit logs are written into two separate disks.
Regards,
Amlan
Re: Table design for historical data
I will be writing an event when device connects. Probably a device never disconnects till current time, and I want to return that device for that time range. Device disconnect is used to mark the end time; Any query beyond that time should not return that device. Queries can have adhoc start and end times. But fixed size buckets can be an option, if it provides better design, even if with a little client overhead. This is not a regular time-series event; in the sense, that there wont be too many device connect/disconnect. We cannot say for sure there will be x events per second. Device disconnects, only if it is down and administrator removes it/replaces it with a different device. That is the reason I am calling it historical state information. I want to know details of device connected to the platform for any given interval. Regards, Firdousi On Wed, Apr 1, 2015 at 11:42 PM, Eric R Medley emed...@xylocore.com wrote: Firdousi, What kind of events would be stored in the table? Will you be writing an event when a device connects and another when it disconnects or will you write a single event after the device finally disconnects? Also, for your queries, do you want ad-hoc start and end times or do you have a known fixed sized interval that could be used to put these events into buckets? How many events would you expect during a fixed interval or how many events per second? Do you know all of the ways that you want to query this data? You may want to write the events out to separate tables in order to satisfy those queries. Regards, Eric R Medley On Apr 1, 2015, at 10:54 AM, Firdousi Farozan ffaro...@gmail.com wrote: Hi, My requirement is to design a table for historical state information (not exactly time-series). For ex: I have devices connecting and disconnecting to the management platform. I want to know the details such as (name, mac, os, image, etc.) for all devices connected to the management platform in a given interval (start and end time). Any help on table design for this use-case? Regards, Firdousi
Re: Why select returns tombstoned results?
Unfortunately I'm using 2.1.2. Is it possible that I downgrade to 2.0.13 without wiping out the data? I'm worrying about if there is a bug in 2.1.2. On Tue, Mar 31, 2015 at 4:37 AM, Paulo Ricardo Motta Gomes paulo.mo...@chaordicsystems.com wrote: What version of Cassandra are you running? Are you by any chance running repairs on your data? On Mon, Mar 30, 2015 at 5:39 PM, Benyi Wang bewang.t...@gmail.com wrote: Thanks for replying. In cqlsh, if I change to Quorum (Consistency quorum), sometime the select return the deleted row, sometime not. I have two virtual data centers: service (3 nodes) and analytics(4 nodes collocate with Hadoop data nodes).The table has 3 replicas in service and 2 in analytics. When I wrote, I wrote into analytics using local_one. So I guest the data may not replicated to all nodes yet. I will try to use strong consistency for write. On Mon, Mar 30, 2015 at 11:59 AM, Prem Yadav ipremya...@gmail.com wrote: Increase the read CL to quorum and you should get correct results. How many nodes do you have in the cluster and what is the replication factor for the keyspace? On Mon, Mar 30, 2015 at 7:41 PM, Benyi Wang bewang.t...@gmail.com wrote: Create table tomb_test ( guid text, content text, range text, rank int, id text, cnt int primary key (guid, content, range, rank) ) Sometime I delete the rows using cassandra java driver using this query DELETE FROM tomb_test WHERE guid=? and content=? and range=? in Batch statement with UNLOGGED. CONSISTENCE_LEVEL is local_one. But if I run SELECT * FROM tomb_test WHERE guid='guid-1' and content='content-1' and range='week' or SELECT * FROM tomb_test WHERE guid='guid-1' and content='content-1' and range='week' and rank = 1 The result shows the deleted rows. If I run this select, the deleted rows are not shown SELECT * FROM tomb_test WHERE guid='guid-1' and content='content-1' If I run delete statement in cqlsh, the deleted rows won't show up. How can I fix this? -- *Paulo Motta* Chaordic | *Platform* *www.chaordic.com.br http://www.chaordic.com.br/* +55 48 3232.3200
Re: replace_address vs add+removenode
In both cases node needs to bootstrap and get data frm other nodes. Removenode has an additional cost as it will lead to additional redistribution of tokens such that all data resides on remaining nodes as per the replication strategy. On removenode, remaining nodes will stream data amongst themselves so that ranges for which dead node was responsible is taken care. Anuj Wadehra From:Ulrich Geilmann ulrich.geilm...@freiheit.com Date:Wed, 1 Apr, 2015 at 9:58 pm Subject:replace_address vs add+removenode Hi. The documentation suggests to use the replace_address startup parameter for replacing a dead node. However, it doesn't motivate why this is superior over adding a new node and retiring the dead one using nodetool removenode. I assume it can be more efficient since the new node can take over the exact tokens of the dead node. Are there any other differences? Can it be reasonable to not use replace_address in the interest of more uniform operations? br, Ulrich
Re: replace_address vs add+removenode
On Wed, Apr 1, 2015 at 9:26 AM, Ulrich Geilmann ulrich.geilm...@freiheit.com wrote: I assume it can be more efficient since the new node can take over the exact tokens of the dead node. Are there any other differences? That's the reason. You get one streaming operation (bootstrap a new node with the same tokens as the old one) instead of two (first, remove this node *and give its data to other nodes*. then, bootstrap a new node with new random tokens.). =Rob
Re: Frequent timeout issues
On Wed, Apr 1, 2015 at 8:37 AM, Amlan Roy amlan@cleartrip.com wrote: Replication factor is 2. It is relatively unusual for people to use a replication factor of 2, for what it's worth. =Rob
Re: Table design for historical data
Firdousi, What kind of events would be stored in the table? Will you be writing an event when a device connects and another when it disconnects or will you write a single event after the device finally disconnects? Also, for your queries, do you want ad-hoc start and end times or do you have a known fixed sized interval that could be used to put these events into buckets? How many events would you expect during a fixed interval or how many events per second? Do you know all of the ways that you want to query this data? You may want to write the events out to separate tables in order to satisfy those queries. Regards, Eric R Medley On Apr 1, 2015, at 10:54 AM, Firdousi Farozan ffaro...@gmail.com wrote: Hi, My requirement is to design a table for historical state information (not exactly time-series). For ex: I have devices connecting and disconnecting to the management platform. I want to know the details such as (name, mac, os, image, etc.) for all devices connected to the management platform in a given interval (start and end time). Any help on table design for this use-case? Regards, Firdousi
Re: Frequent timeout issues
Are you writing multiple cf at same time? Please run nodetool tpstats to make sure that FlushWriter etc doesnt have high All time blocked counts. A Blocked memtable FlushWriter may block/drop writes. If thats the case you may need to increase memtable flush writers..if u have many secondary indexes in cf ..make sure that memtable flush que size is set at least equal to no of indexes.. monitoring iostat and gc logs may help.. Thanks Anuj Wadehra From:Amlan Roy amlan@cleartrip.com Date:Wed, 1 Apr, 2015 at 9:27 pm Subject:Re: Frequent timeout issues Did not see any exception in cassandra.log and system.log. Monitored using JConsole. Did not see anything wrong. Do I need to see any specific info? Doing almost 1000 writes/sec. HBase and Cassandra are running on different clusters. For cassandra I have 6 nodes with 64GB RAM(Heap is at default setting) and 32 cores. On 01-Apr-2015, at 8:43 pm, Eric R Medley emed...@xylocore.com wrote:
Re: Testing sstableloader between Cassandra 2.1 DSE and community edition 2.1
On 04/01/2015 08:10 AM, Serega Sheypak wrote: Sorry cluster1 community version is: ii cassandra 2.1.3 distributed storage system for structured data cluster2 DSE version is: ii dse-libcassandra4.6.2-1 The DataStax Enterprise package includes a production-certifie Mixing versions of Cassandra may not work out well and isn't recommended. DSC 4.6 is Cassandra 2.0.X. -- Michael
Re: Testing sstableloader between Cassandra 2.1 DSE and community edition 2.1
Got it. 2015-04-01 20:39 GMT+02:00 Michael Shuler mich...@pbandjelly.org: On 04/01/2015 08:10 AM, Serega Sheypak wrote: Sorry cluster1 community version is: ii cassandra 2.1.3 distributed storage system for structured data cluster2 DSE version is: ii dse-libcassandra4.6.2-1 The DataStax Enterprise package includes a production-certifie Mixing versions of Cassandra may not work out well and isn't recommended. DSC 4.6 is Cassandra 2.0.X. -- Michael
Re: Cross-datacenter requests taking a very long time.
What type of snitch are you using for cassandra.yaml: endpoint_snitch ? PropertyFileSnitch can improve performance. - bharat On Tue, Mar 31, 2015 at 1:59 PM, daemeon reiydelle daeme...@gmail.com wrote: What is your replication factor? Any idea how much data has to be processed under the query? With that few nodes (3) in each DC, even with replication=1, you are probably not getting much inter-node data transfer in a local quorum, until of course you do cross data centers and at least one full copy of the data has to come across the wire. While running the query against both DC's, you can take a look at netstats to get a really quick-and-dirty idea of network traffic. *...* *“Life should not be a journey to the grave with the intention of arriving safely in apretty and well preserved body, but rather to skid in broadside in a cloud of smoke,thoroughly used up, totally worn out, and loudly proclaiming “Wow! What a Ride!” - Hunter ThompsonDaemeon C.M. ReiydelleUSA (+1) 415.501.0198 %28%2B1%29%20415.501.0198London (+44) (0) 20 8144 9872 %28%2B44%29%20%280%29%2020%208144%209872* On Tue, Mar 31, 2015 at 1:54 PM, Andrew Vant andrew.v...@rackspace.com wrote: I have a Cassandra 2.0.13 cluster with three datacenters, three nodes per datacenter. If I open cqlsh and do a select with any consistency level that crosses datacenters (e.g. QUORUM or ALL), it works, but takes 2+ minutes to return. The same statement with consistency ONE or LOCAL_QUORUM is as fast as it should be. It does not appear to be latency between centers; I can point cqlsh at a server in a different DC and it's not noticeably slow. I tried turning tracing on to get a better idea of what was happening; but it complains `Session long hex string wasn't found`. I'm not entirely sure what direction to look in to find the problem. -- Andrew
Re: SSTable structure
Hi Serega, Most of the content in the blog article is still relevant. After 1.2.5 (ic), there are only three new versions (ja, jb, ka) for SSTable format. Following are the changes in these versions. // ja (2.0.0): super columns are serialized as composites (note that there is no real format change, // this is mostly a marker to know if we should expect super columns or not. We do need // a major version bump however, because we should not allow streaming of super columns // into this new format) // tracks max local deletiontime in sstable metadata // records bloom_filter_fp_chance in metadata component // remove data size and column count from data file (CASSANDRA-4180) // tracks max/min column values (according to comparator) // jb (2.0.1): switch from crc32 to adler32 for compression checksums // checksum the compressed data // ka (2.1.0): new Statistics.db file format // index summaries can be downsampled and the sampling level is persisted // switch uncompressed checksums to adler32 // tracks presense of legacy (local and remote) counter shards - bharat On Wed, Apr 1, 2015 at 12:02 AM, Serega Sheypak serega.shey...@gmail.com wrote: Hi bharat, you are talking about Cassandra 1.2.5 Does it fit Cassandra 2.1? Were there any significant changes to SSTable format and layout? Thank you, article is interesting. Hi jacob jacob.rho...@me.com, HBase does it for example. http://hbase.apache.org/book.html#_hfile_format_2 It would be great to give general ideas. It could help to understand schema design problems. You start to understand better how Cassandra scans data how you can utilize its power. 2015-04-01 5:39 GMT+02:00 Bharatendra Boddu bharatend...@gmail.com: Some time back I created a blog article about the SSTable storage format with some code references. Cassandra: SSTable Storage Format http://distributeddatastore.blogspot.com/2013/08/cassandra-sstable-storage-format.html - bharat On Mon, Mar 30, 2015 at 5:24 PM, Jacob Rhoden jacob.rho...@me.com wrote: Yes updating code and documentation can sometimes be annoying, you would only ever maintain both if it were important. It comes down or is having the format of the data files documented for everyone to understand an important thing? __ Sent from iPhone On 31 Mar 2015, at 11:07 am, daemeon reiydelle daeme...@gmail.com wrote: why? Then there are 2 places 2 maintain or get jira'ed for a discrepancy. On Mar 30, 2015 4:46 PM, Robert Coli rc...@eventbrite.com wrote: On Mon, Mar 30, 2015 at 1:38 AM, Pierre pierredev...@gmail.com wrote: Does anyone know if there is a more complete and up to date documentation about the sstable files structure (data, index, stats etc.) than this one : http://wiki.apache.org/cassandra/ArchitectureSSTable No, there isn't. Unfortunately you will have to read the source. I'm looking for a full specification, with schema of the structure if possible. It would be nice if such fundamental things were documented, wouldn't it? =Rob
Re: Why select returns tombstoned results?
All servers are running ntpd. I guess the time should be synced across all servers. My dataset is too large to use sstable2json. It would take long time. I will try to repair to see if the issue is gone. On Tue, Mar 31, 2015 at 7:49 AM, Ken Hancock ken.hanc...@schange.com wrote: Have you checked time sync across all servers? The fact that you've changed consistency levels and you're getting different results may indicate something inherently wrong with the cluster such as writes being dropped or time differences between the nodes. A brute-force approach to better understand what's going on (especially if you have an example of the wrong data being returned) is to do a sstable2json on all your tables and simply grep for an example key. On Mon, Mar 30, 2015 at 4:39 PM, Benyi Wang bewang.t...@gmail.com wrote: Thanks for replying. In cqlsh, if I change to Quorum (Consistency quorum), sometime the select return the deleted row, sometime not. I have two virtual data centers: service (3 nodes) and analytics(4 nodes collocate with Hadoop data nodes).The table has 3 replicas in service and 2 in analytics. When I wrote, I wrote into analytics using local_one. So I guest the data may not replicated to all nodes yet. I will try to use strong consistency for write. On Mon, Mar 30, 2015 at 11:59 AM, Prem Yadav ipremya...@gmail.com wrote: Increase the read CL to quorum and you should get correct results. How many nodes do you have in the cluster and what is the replication factor for the keyspace? On Mon, Mar 30, 2015 at 7:41 PM, Benyi Wang bewang.t...@gmail.com wrote: Create table tomb_test ( guid text, content text, range text, rank int, id text, cnt int primary key (guid, content, range, rank) ) Sometime I delete the rows using cassandra java driver using this query DELETE FROM tomb_test WHERE guid=? and content=? and range=? in Batch statement with UNLOGGED. CONSISTENCE_LEVEL is local_one. But if I run SELECT * FROM tomb_test WHERE guid='guid-1' and content='content-1' and range='week' or SELECT * FROM tomb_test WHERE guid='guid-1' and content='content-1' and range='week' and rank = 1 The result shows the deleted rows. If I run this select, the deleted rows are not shown SELECT * FROM tomb_test WHERE guid='guid-1' and content='content-1' If I run delete statement in cqlsh, the deleted rows won't show up. How can I fix this? -- *Ken Hancock *| System Architect, Advanced Advertising SeaChange International 50 Nagog Park Acton, Massachusetts 01720 ken.hanc...@schange.com | www.schange.com | NASDAQ:SEAC http://www.schange.com/en-US/Company/InvestorRelations.aspx Office: +1 (978) 889-3329 | [image: Google Talk:] ken.hanc...@schange.com | [image: Skype:]hancockks | [image: Yahoo IM:]hancockks[image: LinkedIn] http://www.linkedin.com/in/kenhancock [image: SeaChange International] http://www.schange.com/This e-mail and any attachments may contain information which is SeaChange International confidential. The information enclosed is intended only for the addressees herein and may not be copied or forwarded without permission from SeaChange International.
Re: How to store unique visitors in cassandra
Very interesting. I had saved your email from three years ago in hopes of an elegant answer. Thanks for sharing! Jim On Tue, Mar 31, 2015 at 8:16 AM, Alain RODRIGUEZ arodr...@gmail.com wrote: People keep asking me if we finally found a solution (even if this is 3+ years old) so I will just update this thread with our findings. We finally achieved doing this thanks to our bigdata and reporting stacks by storing blobs corresponding to HLL (HyperLogLog) structures. HLL is an algorithm used by Google, twitter and many more to solve count-distinct problems. Structures built through this algorithm can be summed and give a good approximation of the UV number. Precision you will reach depends on the size of structure you chose (predictable precision). You can reach fairly acceptable approximation with small data structures. So we basically store a HLL per hour and just sum HLL for all the hours between 2 ranges (you can do it at day level or any other level depending on your needs). Hope this will help some of you, we finally had this (good) idea after more than 3 years. Actually we use HLL for a long time but the idea of storing HLL structures instead of counts allow us to request on custom ranges (at the price of more intelligence on the reporting stack that must read and smartly sum HLLs stored as blobs). We are happy with it since. C*heers, Alain 2012-01-19 22:21 GMT+01:00 Milind Parikh milindpar...@gmail.com: You might want to look at the code in countandra.org; regardless of whether you use it. It use a model of dynamic composite keys (although static composite keys would have worked as well). For the actual query,only one row is hit. This of course only works bc the data model is attuned for the query. Regards Milind /*** sent from my android...please pardon occasional typos as I respond @ the speed of thought / On Jan 19, 2012 1:31 AM, Alain RODRIGUEZ arodr...@gmail.com wrote: Hi thanks for your answer but I don't want to add more layer on top of Cassandra. I also have done all of my application without Countandra and I would like to continue this way. Furthermore there is a Cassandra modeling problem that I would like to solve, and not just hide. Alain 2012/1/18 Lucas de Souza Santos lucas...@gmail.com Why not http://www.countandra.org/ ...
