>
> Because they are occurring in parallel.
>
So if a range is out of sync between A<->B and A<->C, A will receive the
repairing stream from both (in any order) and will apply mutations based on
that and the usual overwrite rules so necessarily exclude one of the
repairing stream and that data will
>
> Because they are occurring in parallel.
>>
> So if a range is out of sync between A<->B and A<->C, A will receive the
> repairing stream from both (in any order) and will apply mutations based on
> that and the usual overwrite rules so necessarily exclude one of the
> repairing stream and that
Hi,
We're currently in the planning stage of a new project which needs a low
latency, persistent key/value store with a roughly 60:40 read/write split.
We're trying to establish if Cassandra is a good fit for this and in particular
what the hardware requirements would be to have the majority of
thanks a lot for all the help! I have gone through the steps and
successfully brought up the node2 :)
On Thu, Aug 18, 2011 at 10:51 AM, Boris Yen wrote:
> Because the file only preserve the "key" of records, not the whole record.
> Records for those saved key will be loaded into cassandra durin
Somewhere I remember discussions about issues with the merkle tree range
splitting or some such that resulted in repair always thinking a little bit of
data was out of sync.
If you want to get a better idea about what's been transfered turn the logging
up to DEBUG or turn it up just for org.ap
IIRC cassandra 0.7 needs thrift 0.5, are you using that version ?
Perhaps try grabbing the cassandra 0.7 version for one of the pre built clients
(pycassa, hector etc) to check things work and then check you are using the
same thrift version.
Cheers
-
Aaron Morton
Freelance Ca
Hi All,
I have a program that crunches through around 3 billion calculations. We
store the result of each of these in cassandra to later query once in order
to create some vectors. Our processing is limited by Cassandra now, rather
than the calculations themselves.
I was wondering what settings I
> Q. If we're using read consistency ONE does the read request get sent to all
> nodes in the replica set and the first to reply is returned (i.e. all replica
> nodes will then have that row in their cache), OR does the request only get
> sent to a single node in the replica set? If it's the lat
just found out that changes via cassandra-cli, the schema change didn't
reach node2. and node2 became unreachable
I did as this document:
http://wiki.apache.org/cassandra/FAQ#schema_disagreement
but after that I just got two schema versons:
ddcada52-c96a-11e0-99af-3bd951658d61: [node1, nod
--
All the best,
Bruno Sinkovic
Office : +31.20.893.2375
Mobile: +31.631.644.719
Skype: bruno.sinkovic
Fax: +31.20.203.1189
Where is your bottleneck?
http://spyced.blogspot.com/2010/01/linux-performance-basics.html
On Thu, Aug 18, 2011 at 6:08 AM, Paul Loy wrote:
> Hi All,
>
> I have a program that crunches through around 3 billion calculations. We
> store the result of each of these in cassandra to later query once i
Hi All,
This is regarding help to resolve "connection refused error" on Cassandra
client API.
I have installed cassandra-0.8.4 on three machines and tried to upload a file
from HDFS to Cassandra by Hadoop map-reduce program and have caught up
"connection refused" error.
But, the same code is
What is rpc_address set to in cassandra.yaml?
Try setting these to 0.0.0.0 to be sure it's listening to external traffic.
On Thu, Aug 18, 2011 at 8:37 AM, Thamizh wrote:
> Hi All,
>
> This is regarding help to resolve "connection refused error" on Cassandra
> client API.
>
> I have installed ca
Hi Paul,
Here's one idea: If you're going to write just once then read once after the
writes are finished, then you could disable minor compactions whilst
performing the writes. This will mean that all disk IO bandwidth will be
available for writes. After you have finished writing, re-enable minor
On Thu, Aug 18, 2011 at 5:01 AM, Stephen Henderson <
stephen.hender...@cognitivematch.com> wrote:
> Hi,
>
> We're currently in the planning stage of a new project which needs a low
> latency, persistent key/value store with a roughly 60:40 read/write split.
> We're trying to establish if Cassandra
Are you writing lots of tiny rows or a few very large rows, are you batching
mutations? is the loading disk or cpu or network bound?
-Jake
On Thu, Aug 18, 2011 at 7:08 AM, Paul Loy wrote:
> Hi All,
>
> I have a program that crunches through around 3 billion calculations. We
> store the result o
Philippe,
Besides the system keyspace, we have only one user keyspace. However, tell
me that we can also try repairing one CF at a time.
We have two concurrent compactors configured. Will change that to one.
Huy
On Wed, Aug 17, 2011 at 6:10 PM, Philippe wrote:
> Huy,
> Have you tried repai
Unfortunately repairing one cf at a time didn't help in my case because it
still streams all CF and that triggers lots of compactions
On Aug 18, 2011 3:48 PM, "Huy Le" wrote:
Thanks Ed/Aaron, that really helped a lot.
Just to clarify on the question of writes (sorry, I worded that badly) - do
write operations insert rows into the cache on all nodes in the replica set or
does the cache only get populated on reads?
Aaron - in terms of scale, our ultimate goal is to ac
I am running cassandra 0.7.8. pycassa 1.1.0
Nodes=7, RF=3
This problem started a few months ago and only occurs sporadically.
I receive notifications from paypal's IPN. The IPN data is saved into
a column family. I add another column for "processed" which is set to
0.
Every 5 minutes, a cron sc
Yeah, we're processing item similarities. So we are writing single columns
at a time. Although we do batch these into 400 mutations before sending to
Cassy. We currently perform almost 2 billion calculations that then write
almost 4 billion columns.
Once all similarities are calculated, we just gr
So you only have 1 cassandra node?
If you are interested only in getting the complete work done as fast as
possible before you begin reading, take a look at the new bulk loader in
cassandra:
http://www.datastax.com/dev/blog/bulk-loading
-Jake
On Thu, Aug 18, 2011 at 11:03 AM, Paul Loy wrote:
Hi All
I have not been able to list the contents of an existing Column Family:
[default@MyKeySpace] Describe keyspace MyKeySpace;
Keyspace: MyKeySpace:
Replication Strategy:
org.apache.cassandra.locator.NetworkTopologyStrategy
Options: [datacenter1:1]
Column Families:
ColumnFamily
On Thu, Aug 18, 2011 at 10:36 AM, Stephen Henderson <
stephen.hender...@cognitivematch.com> wrote:
> Thanks Ed/Aaron, that really helped a lot.
>
>
>
> Just to clarify on the question of writes (sorry, I worded that badly) - do
> write operations insert rows into the cache on all nodes in the repl
There are a lot of people on 0.7 for whom CL is working as advertised.
Not saying it's impossible that there's a bug, but the odds are
against it.
Is it possible for instance that sometimes your cron job takes longer
than five minutes?
On Thu, Aug 18, 2011 at 9:49 AM, Kyle Gibson
wrote:
> I am
Step 0: use multiple threads to insert
On Thu, Aug 18, 2011 at 10:03 AM, Paul Loy wrote:
> Yeah, we're processing item similarities. So we are writing single columns
> at a time. Although we do batch these into 400 mutations before sending to
> Cassy. We currently perform almost 2 billion calcula
Hi Jake,
Thanks a lot.
I have done the below modification as you pointed out.
Once, I do the modification on cassandra.yaml does it require to restart the
cassandra service?
Now, I am getting below error, (attached cassandra.yaml)
11/08/18 10:35:18 INFO mapred.JobClient: map 100% reduce 0%
Yup, we do that. We currently have 200 threads that push mutations into a
pool of Mutators (think Pelops - although that was too slow so we rolled our
own much lower level version). We have around 50 thrift clients that
mutations are them pushed through to cassandra.
On Thu, Aug 18, 2011 at 4:35 P
https://issues.apache.org/jira/browse/CASSANDRA-3054
On Wed, Aug 17, 2011 at 7:13 PM, aaron morton wrote:
> ooo, didn't know there was a drop index statement.
>
> I got the same result, the Antlr grammar seems to say it's a valid
> identifier (not that I have much Antlr foo)…
>
>
> Identifier
>
Yeah, the data after crunching drops to just 65000 columns so one Cassandra
is plenty. That will all go in memory on one box. It's only the crunching
where we have lots of data and then need it arranged in a structured manner.
That's why I don't use flat files that I just append to. I need them in
All,
One node in my cluster returns a different answer for nodetool ring. It
seems to be ignorant of one of the other nodes. I've verified that all nodes
can ping each other without difficulty.
Here is the proper response:
Address DC RackStatus State LoadO
Hi
I'm trying to test a single issue:
https://issues.apache.org/jira/browse/CASSANDRA-674
But when I downloaded the patch file I can't find the correct trunk to patch...
Anyone can help me with it? Thanks
Steve
Thanks. I won't try that then.
So in our environment, after upgrading from 0.6.11 to 0.8.4, we have to run
scrub on all nodes before we can run repair on them. Is there any chance
that running scrub on the nodes causing data from all SSTables being
streamed to/from other nodes on running repair?
Hi,
Is it normal that the repair takes 4+ hours for every node, with only about 10G
data? If this is not expected, do we have any hint what could be causing this?
The ring looks like below, we're using 0.8.1. Our repair is scheduled to run
once per week for all nodes.
Compaction related config
I am in the process of trying to tune the memtable flush thresholds for a
particular column family (super column family to be specific) in my
Cassandra 0.8.1 cluster. This CF is reasonably heavily used and getting
flushed roughly every 5-8 minutes which is hardly optimal, particularly
given I have
See http://thelastpickle.com/2011/05/04/How-are-Memtables-measured/,
specifically the section on memtable_total_space_in_mb
On Thu, Aug 18, 2011 at 2:43 PM, Dan Hendry wrote:
> I am in the process of trying to tune the memtable flush thresholds for a
> particular column family (super column famil
Interesting.
Just to clarify, there are three main conditions which will trigger a flush
(based on data size):
1. The serialized size of a memtable exceeds the per CF memtable_throughput
setting.
2. For a single cf: (serialized size)*(live ratio)*(maximum possible
memtables in memory) > memtable_
Look in the logs to work find out why the migration did not get to node2.
Otherwise yes you can drop those files.
Cheers
-
Aaron Morton
Freelance Cassandra Developer
@aaronmorton
http://www.thelastpickle.com
On 18/08/2011, at 11:25 PM, Yan Chunlu wrote:
> just found out that ch
Those numbers sound achievable. As with any scaling start with the default
config and see how you go, a 5ms response time is certainly reasonable as are
the throughput numbers.
e.g. If you started with 6 nodes, rf 3, with read repair turned on
20k ops -> 12k reads and 8k writes
X3 because of
Are you using 0.0.0.0 in your mapred config ? It should be the external IP of
the cassandra node.
0.0.0.0 is just for the rpc_address config.
Cheers
-
Aaron Morton
Freelance Cassandra Developer
@aaronmorton
http://www.thelastpickle.com
On 19/08/2011, at 3:35 AM, Thamizh wro
couple of thoughts, 400 row mutations in a batch may be a bit high. More is not
always better. Watch the TP stats to see if the mutation pool is backing up
excessively.
Also if you feel like having fun take a look at the durable_writes config
setting for keyspaces, from the cli help…
- durable
Try a restart on that guy with and with the JVM option
-dcassandra.load_ring_state=false (see cassandra-env.sh).
If that does not fix it….
http://www.datastax.com/docs/0.8/troubleshooting/index#view-of-ring-differs-between-some-nodes
Cheers
-
Aaron Morton
Freelance Cassandra
No scrub is a local operation only.
Cheers
-
Aaron Morton
Freelance Cassandra Developer
@aaronmorton
http://www.thelastpickle.com
On 19/08/2011, at 6:36 AM, Huy Le wrote:
> Thanks. I won't try that then.
>
> So in our environment, after upgrading from 0.6.11 to 0.8.4, we have
The compactions ettings do not affect repair. (Thinking out loud, or does it ?
Validation compactions and table builds.)
Watch the logs or check
nodetool compactionstats to see when the Validation completes completes.
and
nodetool netstats to see how long the data transfer takes
It sounds a li
We're trying to bootstrap some new nodes and it appears when adding a new node
that there is a lot of logging on hints being flushed and compacted. It's been
taking about 75 minutes thus far to bootstrap for only about 10 GB of data.
It's ballooned up to over 40 GB on the new node. I do 'ls -
Hi,
version - 0.7.4
cluster size = 3
RF = 3.
data size on a node ~500G
I want to do some disk maintenance on a cassandra node, so the process that
I came up with is
- drain this node
- back up the system data space
- rebuild the disk partition
- copy data from another node
- copy
I'm reading the commitLog code since I have some similar logic in my
application code,
so that I could benefit from the same techniques that CommitLog code uses.
I see that
CommitLog.add(RowMutation rowMutation) {
executor.add(new LogRecordAdder(rowMutation));
}
while executor could be th
I would assume it's because it thinks some node is down and is
creating hints for it.
On Thu, Aug 18, 2011 at 6:31 PM, Jeremy Hanna
wrote:
> We're trying to bootstrap some new nodes and it appears when adding a new
> node that there is a lot of logging on hints being flushed and compacted.
> I
There is always a single CLES thread whether for Batch or Periodic.
(For Batch, look for the appendingThread field.)
On Thu, Aug 18, 2011 at 7:41 PM, Yang wrote:
> I'm reading the commitLog code since I have some similar logic in my
> application code,
> so that I could benefit from the same tech
thanks Jonathan, found it
public BatchCommitLogExecutorService(int queueSize)
{
queue = new LinkedBlockingQueue(queueSize);
...
appendingThread = new Thread(runnable, "COMMIT-LOG-WRITER");
appendingThread.start();
}
On Thu, Aug 18, 2011 at 5:5
I've been using Cassandra as a database storage device for a service based
application.
I'm wondering if you can design a multi-tiered cassandra cluster that is
used by both clients and servers.
I'd like to have the ability to setup the following:
*Implement a Core Seed Servers / Nodes internal o
Why not use couchdb for this use case?
Milind
/***
sent from my android...please pardon occasional typos as I respond @ the
speed of thought
/
On Aug 18, 2011 9:07 PM, "Nicholas Neuberger" wrote:
I've been using Cassandra as a database storage device
Hi
I am using 0.7.4 and am seeing this exception my logs a few times a day,
should I be worried? Or is this just a intermittent network disconnect
ERROR [RequestResponseStage:257] 2011-08-19 03:05:30,706
AbstractCassandraDaemon.java (line 112) Fatal exception in thread
Thread[RequestResponseSta
You should get on 0.7.4 while you are doing this, this is a pretty good reason
https://github.com/apache/cassandra/blob/cassandra-0.7.8/CHANGES.txt#L58
> Never done a read repair on this cluster before, is that a problem?
Potentially.
Repair will ensure that your data is distributed, and that d
OrientDB may be a perfect fit for you - a little bit like couch - on
java we use it too - and it's super fast
2011/8/19 Milind Parikh
> Why not use couchdb for this use case?
> Milind
>
> /***
> sent from my android...please pardon occasional typos as I respond @ the
> sp
So if you kill a joining node, it will remain as a Fat Client (as of 0.7.x) in
gossip. That is innocuous on its own. However if a node was decommissioned
while that was joining, then the lingering Fat Client will also gossip about
the node that was decommissioned. Then it will try to hint for
You should run nodetool scrub on the affected nodes. You should
probably seriously consider upgrading to the most recent 0.7 release.
On Thu Aug 18 22:30:36 2011, Anand Somani wrote:
Hi
I am using 0.7.4 and am seeing this exception my logs a few times a day,
should I be worried? Or is this ju
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