Re: coordinator failure handling

This will depend on what driver you're using at the client. The Java driver, for example, has ways to configure each of the things you mentioned, with a variety of implementations you can choose from. There are also ways to provide your own custom implementation if you don't like the options

Re: [EXTERNAL] Howto avoid tombstones when inserting NULL values

Depending on the use case, creating separate prepared statements for each combination of set / unset values in large INSERT/UPDATE statements may be prohibitive. Instead, you can look into driver level support for UNSET values. Requires Cassandra 2.2 or later IIRC. See: Java Driver:

Re: Optimizing for connections

RE #2, some have had good results from having coordinator-only nodes: https://www.slideshare.net/DataStax/optimizing-your-cluster-with-coordinator-nodes-eric-lubow-simplereach-cassandra-summit-2016 Assuming finite resources, it might be better to be certain you have good token awareness in your

Re: Multiple cluster for a single application

We are engaging in both strategies at the same time: 1) We call it functional sharding - we write to clusters targeted according to the type of data being written. Because different data types often have different workloads this has the nice side effect of being able to tune each cluster

Re: A quick question on unlogged batch

I know this is the official recommendation, and has been for a while. I highly recommend testing it for yourself though, as our own testing has shown that for _most_ versions of Cassandra (not all), unlogged batch meaningfully outperforms parallel execution of individual statements, especially at

Re: estimated number of keys vs ttl

I believe that key estimates won't immediately respond to expired TTL, Not until after compaction has completely dropped the records (which will include subtle logic related to gc_grace and partitions with data in multiple SSTables). On Wed, May 23, 2018 at 6:18 AM Rahul Singh

Re: Cassandra java driver linux encoding issue

What is the value returned from Charset.defaultCharset() on both systems? On Wed, May 16, 2018 at 5:00 AM rami dabbah wrote: > Hi, > > I am trying to query text filed from Cassandra using java driver see code > below. In windows it is working fine but in linux i am getting

Re: Trying to save in cassandra with "SomeColumns"

You can fill in var-args with SomeColumns(myColumns:_*) style syntax. See for example: https://stackoverflow.com/questions/1832061/scala-pass-seq-to-var-args-functions On Fri, Mar 30, 2018 at 6:15 PM Guillermo Ortiz wrote: > > The poblem is that I have a method from Spark

Re: Performance Of IN Queries On Wide Rows

Someone can correct me if I'm wrong, but I believe if you do a large IN() on a single partition's cluster keys, all the reads are going to be served from a single replica. Compared to many concurrent individual equal statements you can get the performance gain of leaning on several replicas for

Re: Old tombstones not being cleaned up

Hi, Just in case you haven't seen it, I gave a talk last year at the summit. In the first part of the talk I speak for a while about the lifecycle of a tombstone, and how they don't always get cleaned up when you might expect. https://youtu.be/BhGkSnBZgJA It looks like you're deleting cluster

Re: Add column if it does not exist?

To hop on what Jon said, if your concern is automatic application of schema migrations, you want to be very careful with this. I'd consider it an unsolved problem in Cassandra for some methods of schema application. The failed ALTER is not what you have to worry about, it's two successful ALTERs

Re: BATCH OPERATION issue

The original timestamp is bigger than the timestamp you're using in your batch. Cassandra uses timestamps for conflict resolution, so the batch write will lose. On Wed, Sep 13, 2017 at 11:59 AM Deepak Panda wrote: > Hi All, > > Am in the process of learning batch

Re: Getting all unique keys

You should be able to fairly efficiently iterate all the partition keys like: select id, token(id) from table where token(id) >= -9204925292781066255 limit 1000; id | system.token(id) +-- ...

Re: 1 node doing compaction all the time in 6-node cluster (C* 2.2.8)

We've seen an unusually high instance failure rate with i3's (underlying hardware degradation). Especially with the nodes that have been around longer (recently provisioned nodes have a more typical failure rate). I wonder if your underlying hardware is degraded and EC2 just hasn't noticed yet.

Re: Multi datacenter node loss

> If using the SimpleStrategy replication class, it appears that > replication_factor is the only option, which applies to the entire > cluster, so only one node in both datacenters would have the data. This runs counter to my understanding, or else I'm not reading your statement correctly. When

Re: The changing clustering key

Just curious if you've looked at materialized views. Something like: CREATE MATERIALIZED VIEW users_by_mod_date AS SELECT dept_id,mod_date,user_id,user_name FROM users WHERE mod_date IS NOT NULL PRIMARY KEY (dept_id,mod_date,user_id) WITH CLUSTERING ORDER BY (mod_date

Re: Effective partition key for time series data, which allows range queries?

Jim's basic model is similar to how we've solved this exact kind of problem many times. From my own experience, I strongly recommend that you make a `bucket` field in the partition key, and a `time` field in the cluster key. Make both of these of data type `timestamp`. Then use application

Re: How can I scale my read rate?

<alf.mmm@gmail.com> wrote: On 24/03/2017 01:00, Eric Stevens wrote: > Assuming an even distribution of data in your cluster, and an even > distribution across those keys by your readers, you would not need to > increase RF with cluster size to increase read performance. If you

Re: How can I scale my read rate?

Assuming an even distribution of data in your cluster, and an even distribution across those keys by your readers, you would not need to increase RF with cluster size to increase read performance. If you have 3 nodes with RF=3, and do 3 million reads, with good distribution, each node has served

Re: Is it possible to recover a deleted-in-future record?

Those future tombstones are going to continue to cause problems on those partitions. If you're still writing to those partitions, you might be losing data in the mean time. It's going to be hard to get the tombstone out of the way so that new writes can begin to happen there (newly written data

Re: Pluggable throttling of read and write queries

> We’ve actually had several customers where we’ve done the opposite - split large clusters apart to separate uses cases We do something similar but for a single application. We're functionally sharding data to different clusters from a single application. We can have different server classes

Re: WriteTimeoutException when doing paralel DELETE IF EXISTS

This question is probably better suited for the user@ group. It doesn't sound to me like you've uncovered a bug, but rather you're engaging in highly contentious paxos, which is rarely going to have a favorable outcome. Likely you're overwhelming your cluster (or more specifically the replicas

Re: Insert with both TTL and timestamp behavior

The purpose of timestamps is to guarantee out-of-order conflicting writes are resolved as last-write-wins. Cassandra doesn't really expect you to be writing timestamps with wide variations from record to record. Indeed, if you're doing this, it'll violate some of the assumptions in places such

Re: FW: Cassandra trigger to send notifications

You probably want to look at change data capture rather than triggers: http://cassandra.apache.org/doc/latest/operating/cdc.html Be aware that one of your criteria regarding operation order is going to be very difficult to guarantee due to eventual consistency. On Fri, Dec 16, 2016, 2:43 AM

Re: Handle Leap Seconds with Cassandra

You're able to set the timestamp of the write in the client application. If you have a table which is especially sensitive to out of order writes and want to deal with the repeated second correctly, you could do slewing at your client application layer and be explicit with the timestamp for those

Re: Running Cassandra in Integration Tests

If you happen to be using Scala, we recently released some tooling we wrote around using CCM for integration testing: https://github.com/protectwise/cassandra-util You define clusters and nodes in configuration, then ask the service to go:

Re: How to write a trigger in Cassandra to only detect updates of an existing row?

You would have to perform a SELECT on the row in the trigger code in order to determine if there was underlying data. Cassandra is in essence an append-only data store, when an INSERT or UPDATE is executed, it has no idea if there is already a row underlying it, and for write performance reasons

Re: Way to write to dc1 but keep data only in dc2

It sounds like you're trying to avoid the latency of waiting for a write confirmation to a remote data center? App ==> DC1 ==high-latency==> DC2 If you need the write to be confirmed before you consider the write successful in your application (definitely recommended unless you're ok with losing

Re: Using keyspaces for virtual clusters

Using keyspaces to support multi tenancy is very close to an anti pattern unless there is a finite and reasonable upper bound to how many tenants you'll support overall. Large numbers of tables comes with cluster overhead and operational complexity you will come to regret eventually. >and because

Re: Overhead of data types in cassandra

It's important to note that this answer differs quite significantly depending on whether you're talking about Cassandra < 3.0 or >= 3.0 DataStax has a good article on < 3.0: http://docs.datastax.com/en/cassandra/2.0/cassandra/architecture/architecturePlanningUserData_t.html The Last Pickle has a

Re: Finding records that exist on Cassandra but not externally

I might be inclined to include a generation ID in the partition keys. Keep a separate table where you upgrade the generation ID when your processing is complete. You can even use CAS operations in case you goofed up and generated two generations at the same time (or your processing time exceeds

Re: Return value of newQueryPlan

was referring to Java driver. > I used DCAwareRoundRobin, TokenAware Policy for application flow. > Would ask question1 on driver mailing list, If someone could help with > question 2. > > > > > > > > > > > On Fri, Sep 2, 2016 at 6:59 PM, Eric Stevens <mig

Re: Merging cells in compaction / compression?

When you say merge cells, do you mean re-aggregating the data into courser time buckets? On Thu, Aug 4, 2016 at 5:59 AM Michael Burman wrote: > Hi, > > Considering the following example structure: > > CREATE TABLE data ( > metric text, > value double, > time timestamp, >

Re: Re : Purging tombstones from a particular row in SSTable

t doesn't say nothing about iterating all cells in a single partition > if having a partition tombstone, I need to dig further > > > > > On Sat, Jul 30, 2016 at 2:03 AM, Eric Stevens <migh...@gmail.com> wrote: > >> I haven't tested that specifically, but I ha

Re: Re : Purging tombstones from a particular row in SSTable

the whole partition (let's limit the example to a > single SSTable) ? > > On Fri, Jul 29, 2016 at 7:00 PM, Eric Stevens <migh...@gmail.com> wrote: > >> > Sai was describing a timeout, not a failure due to the 100 K tombstone >> limit from cassandra.yaml. But I st

Re: Re : Purging tombstones from a particular row in SSTable

his still sounds very weird to me but I am glad you solved your issue > (temporary at least). > > C*heers, > --- > Alain Rodriguez - al...@thelastpickle.com > France > > The Last Pickle - Apache Cassandra Consulting > http://www.thelastpickle.co

Re: Re : Purging tombstones from a particular row in SSTable

Tombstones will not get removed even after gc_grace if bloom filters indicate that there is overlapping data with the tombstone's partition in a different sstable. This is because compaction can't be certain that the tombstone doesn't overlap data in that other table. If you're writing to one

Re: Issue in internode encryption in cassandra

Those ciphers are not available on Java 6, on the off chance that you're trying to run Cassandra on that (you'll run into other troubles). The more likely problem is that I think those ciphers are only available if you install the Unlimited Strength JCE policy files in your JVM on each node.

Re: Reason for Trace Message Drop

sually this many column families suggests dynamically creating CF's (eg to solve multi-tenancy). If your CF count will grow steadily over time at any appreciable rate, that's an anti-pattern. On Thu, Jun 16, 2016 at 2:40 AM Varun Barala <varunbaral...@gmail.com> wrote: > Thanks!! Eric Stevens

Re: Cqlsh Questions

There's an effort to improve the docs, but while that's catching up, 3.0 has the latest version of the document you're looking for: https://cassandra.apache.org/doc/cql3/CQL-3.0.html#createKeyspaceStmt On Wed, Jun 15, 2016 at 5:28 AM Steve Anderson wrote: > Couple of

Re: Data lost in Cassandra 3.5 single instance via Erlang driver

As a side note, if you're inserting records quickly enough that you're potentially doing multiple in the same millisecond, it seems likely to me that your partition size is going to be too large at a day level unless your writes are super bursty: ((appkey, pub_date), pub_timestamp). You might

Re: Reason for Trace Message Drop

This is better kept to the User groups. What are your JVM memory settings for Cassandra, and have you seen big GC's in your logs? The reason I ask is because that's a large number of column families, which produces memory pressure, and at first blush that strikes me as a likely cause. On Wed,

Re: Internal Handling of Map Updates

on a row with a map will always > create tombstones :-( > > > > 2016-06-02 2:02 GMT+02:00 Eric Stevens <migh...@gmail.com>: > >> From that perspective, you could also use a frozen collection which takes >> away the ability to append, but for which overwrite

Re: Internal Handling of Map Updates

JSON instead of a collection? > > On 27 May 2016 at 15:20, Eric Stevens <migh...@gmail.com> wrote: > >> If you aren't removing elements from the map, you should instead be able >> to use an UPDATE statement and append the map. It will have the same effect >> as overw

Re: Per node limit for Disk Space

Those are rough guidelines, actual effective node size is going to depend on your read/write workload and the compaction strategy you choose. The biggest reason data density per node usually needs to be limited is due to data grooming overhead introduced by compaction. Data at rest essentially

Re: Internal Handling of Map Updates

If you aren't removing elements from the map, you should instead be able to use an UPDATE statement and append the map. It will have the same effect as overwriting it, because all the new keys will take precedence over the existing keys. But it'll happen without generating a tombstone first. If

Re: Too many keyspaces causes cql connection to time out ?

small databases. On Tue, May 24, 2016 at 11:54 AM Justin Lin <linjianfeng...@gmail.com> wrote: > so i guess i have to 1) increase the heap size or 2) reduce the number of > keyspaces/column families. > > Thanks for you confirmation. > > On Tue, May 24, 2016 at 10:0

Re: Cassandra event notification on INSERT/DELETE of records

t; I think this also is an anti-pattern. > > Regards, > Aaditya > > On Tue, May 24, 2016 at 12:45 PM, Mark Reddy <mark.l.re...@gmail.com> > wrote: > >> +1 to what Eric said, a queue is a classic C* anti-pattern. Something >> like Kafka or RabbitMQ might fit y

Re: Thrift client creates massive amounts of network packets

patch the version. Given that it is a single node cluster for the time > being, would your remarks apply to that particular setup? > > > Thanks again! > Ralf > > > On 24.05.2016, at 19:18, Eric Stevens <migh...@gmail.com> wrote: > > I'm not familiar w

Re: Thrift client creates massive amounts of network packets

I'm not familiar with Titan's usage patterns for Cassandra, but I wonder if this is because of the consistency level it's querying Cassandra at - i.e. if CL isn't LOCAL_[something], then this might just be lots of little checksums required to satisfy consistency requirements. On Mon, May 23, 2016

Re: Too many keyspaces causes cql connection to time out ?

Large numbers of tables is generally recommended against. Each table has a fixed on-heap memory overhead, and by your description it sounds like you might have as many as 12,000 total tables when you start running into trouble. With such a small heap to begin with, you've probably used up most

Re: Cassandra event notification on INSERT/DELETE of records

It sounds like you're trying to build a queue in Cassandra, which is one of the classic anti-pattern use cases for Cassandra. You may be able to do something clever with triggers, but I highly recommend you look at purpose-built queuing software such as Kafka to solve this instead. On Tue, May

Re: Traffic inconsistent across nodes

WDC >> >> distance of host: LOCAL >> >> host is up: true >> >> cassandra version : 2.0.17 >> >> host ip: 10.124.114.105 >> >> host DC : WDC >> >> distance of host: LOCAL >> >> host is up: true >> >>

Re: Traffic inconsistent across nodes

10.124.114.98 165.34 GB 256 37.6% > cdc69c7d-b9d6-4abd-9388-1cdcd35d946c RAC1 > > UN 10.124.114.113 145.22 GB 256 35.7% > 1557af04-e658-4751-b984-8e0cdc41376e RAC1 > > UN 10.125.138.59 162.65 GB 256 38.6% > 9ba1b7b6-5655-456e-b1a1-6f429750fc96 RAC1 > &g

Re: Traffic inconsistent across nodes

Maybe include nodetool status here? Are the four nodes serving reads in one DC (local to your driver's config) while the others are in another? On Tue, Apr 12, 2016, 1:01 AM Anishek Agarwal wrote: > hello, > > we have 8 nodes in one cluster and attached is the traffic

Re: How is the coordinator node in LOCAL_QUORUM chosen?

to discovered (if so, how?) or manually specified > somewhere? > * Whether local_xxx consistencies always fail when a partition is not > replicated in the local DC, as specified in its replication strategy. > > Perhaps I should ask the node.js client authors about this. > > > On Mo

Re: Solr and vnodes anyone?

IIRC in DSE 4.6 using vnodes is basically always a bad idea in your Solr datacenter. The overhead was more than you could reasonably want to pay unless your vnode count was low enough that you lost all the advantage. Around 4.7 there were significant performance improvements for vnodes in DSE

Re: How is the coordinator node in LOCAL_QUORUM chosen?

> Local quorum works in the same data center as the coordinator node, but when an app server execute the write query, how is the coordinator node chosen? It typically depends on the driver, and decent drivers offer you several options for this, usually called load balancing strategy. You

Re: Large number of tombstones without delete or update

In addition to writing null values acting as tombstones, also INSERTing a collection (or UPDATE where you set the collection rather than append to it) are also operations which will create tombstones. On Wed, Mar 23, 2016 at 12:09 PM Robert Coli wrote: > On Wed, Mar 23,

Re: Compaction Filter in Cassandra

We have been working on filtering compaction for a month or so (though we call it deleting compaction, its implementation is as a filtering compaction strategy). The feature is nearing completion, and we have used it successfully in a limited production capacity against DSE 4.8 series. Our use

Re: Practical limit on number of column families

It's definitely not true for every use case of a large number of tables, but for many uses where you'd be tempted to do that, adding whatever would have driven your table naming instead as a column in your partition key on a smaller number of tables will meet your needs. This is especially true

Re: automated CREATE TABLE just nuked my cluster after a 2.0 -> 2.1 upgrade....

There's still a race condition there, because two clients could SELECT at the same time as each other, then both INSERT. You'd be better served with a CAS operation, and let Paxos guarantee at-most-once execution. On Tue, Jan 26, 2016 at 9:06 AM Francisco Reyes wrote: > On

Re: automated CREATE TABLE just nuked my cluster after a 2.0 -> 2.1 upgrade....

It seems like this exact problem pops up every few weeks on this list. I think the documentation does a dangerously bad job of describing the limitations of CREATE TABLE...IF NOT EXISTS. CREATE TABLE...IF NOT EXISTS is a dangerous construct because it seems to advertise atomicity and isolation,

Re: Timestamp Query

Generally speaking (both for Cassandra as well as for many other projects), timestamps don't carry a timezone directly. A single point in time has a consistent value for timestamp regardless of the timezone, and when you convert a timestamp to a human-friendly value, you can attach a timezone to

Re: Fail to select ALL the datas in C*

Inconsistent reads are most often the result of inconsistent data between nodes. Inconsistent data during tests like this is quite often the result of having loaded data fast enough that you dropped mutations (writing even at quorum means that you could still be dropping data on some nodes and

Re: Getting code=2200 [Invalid query] message=Invalid column name ... while executing ALTER statement

> 3) check the system.schema_columns if these column_name(s) exist in the table > 4) If the column don't exist in the table "ALTER table tablename add new column_name text" Unless you have some external control on this so that you know two processors will never attempt the same operation within a

Re: Best way to recreate a cassandra node with data

Check nodetool status to see if the replacement node is fully joined (UN status). If it is and it didn't stream any data, then either auto_bootstrap was false, or the node was in its own seeds list. If you lost a node, then replace_address as Jonny mentioned would probably be a good idea. On

Re: why cassanra max is 20000/s on a node ?

> 512G memory , 128core cpu This seems dramatically oversized for a Cassandra node. You'd do *much* better to have a much larger cluster of much smaller nodes. On Thu, Nov 5, 2015 at 8:25 AM Jack Krupansky wrote: > I don't know what current numbers are, but last

Re: Does datastax java driver works with ipv6 address?

The server is binding to the IPv4 "all addresses" reserved address (0.0.0.0), but binding it as IPv4 over IPv6 (:::0.0.0.0), which does not have the same meaning as the IPv6 all addresses reserved IP (being ::, aka 0:0:0:0:0:0:0:0). My guess is you have an IPv4 address of 0.0.0.0 in

Re: Replication Factor Change

If you switch reads to CL=LOCAL_ALL, you should be able to increase RF, then run repair, and after repair is complete, go back to your old consistency level. However, while you're operating at ALL consistency, you have no tolerance for a node failure (but at RF=1 you already have no tolerance for

Re: Cassandra 2.0 Batch Statement for timeseries schema

If you're talking about logged batches, these absolutely have an impact on performance of about 30%. The whole batch will succeed or fail as a unit, but throughput will go down and load will go up. Keep in mind that logged batches are atomic but are not isolated - i.e. it's totally possible to

Re: Question for datastax java Driver

In short: Yes, but it's not a good idea. To do it, you want to look into WhiteListPolicy for your loadbalancer policy, if your WhiteListPolicy contains only the same host(s) that you added as contact points, then the client will only connect to those hosts. However it's probably not a good idea

Re: Doubt regarding consistency-level in Cassandra-2.1.10

The >>> amount of time such an operation takes is greatly increased as well; you >>> may need to increase your internal node-to-node timeouts . >>> >>> On Mon, Nov 2, 2015 at 8:01 PM, Ajay Garg <ajaygargn...@gmail.com> >>> wrote: >>> &

Re: Doubt regarding consistency-level in Cassandra-2.1.10

Serial consistency gets invoked at the protocol level when doing lightweight transactions such as CAS operations. If you're expecting that your topology is RF=2, N=2, it seems like some keyspace has RF=3, and so there aren't enough nodes available to satisfy serial consistency. See

Re: Would we have data corruption if we bootstrapped 10 nodes at once?

It seems to me that as long as cleanup hasn't happened, if you *decommission* the newly joined nodes, they'll stream whatever writes they took back to the original replicas. Presumably that should be pretty quick as they won't have nearly as much data as the original nodes (as they only hold data

Re: LOCAL_SERIAL

ZK seems a little overkill for just 1 feature though. LOCAL_SERIAL is > fine if all you want to do is keep a handful of keys up to date. > > There’s a massive cost in adding something new to your infrastructure, and > imo, very little gain in this case. > > On Oct 15, 2015, at

Re: Accessing dynamic columns via cqlsh

If the columns are not dynamically named (as in "actionId" and "code") you should be able to add that to your CQL table definition with ALTER TABLE, and those columns should be available in the query results. If the columns *are* dynamically named, and you can't reasonably add every option to the

Re: LOCAL_SERIAL

You probably could, but if I were you, I'd consider a tool built for that purpose, such as Zookeeper. It'd open up access to a lot of other great cluster coordination features. On Thu, Oct 15, 2015 at 8:47 AM Jan Algermissen wrote: > Hi, > > suppose I have two data

Re: Cassandra mountable data store

You cannot busy throw bigger and bigger disks at a cluster that is accumulating data as it fills up. This is due to data grooming tasks that increase in cost as your data density per node increases (for example, compaction), as well as other factors that are impacted by data density (such as

Re: Realtime data and (C)AP

The DataStax Java driver is based on Netty and is non blocking; if you do any CQL work you should look into it. At ProtectWise we use it with high write volumes from Scala/Akka with great success. We have a thin Scala wrapper around the Java driver that makes it act more Scalaish (eg, Scala

Re: Is replication possible with already existing data?

If you're at 1 node (N=1) and RF=1 now, and you want to go N=3 RF=3, you ought to be able to increase RF to 3 before bootstrapping your new nodes, with no downtime and no loss of data (even temporary). Effective RF is min-bounded by N, so temporarily having RF > N ought to behave as RF = N. If

Re: Cassandra Configuration VS Static IPs.

Basically your client just needs a route to talk to the IP being broadcast by each node. We do plenty in EC2 and we use the instance private IP in the broadcast address. If you are doing multi-datacenter in EC2 it gets a little harrier, where you need to use the public IP (but not necessarily

Re: Duplicate records returned

Can you give us an example of the duplicate records that comes back? How reliable is it (i.e. is it every record, is it one record per read, etc)? By any chance is it just the `data` field that duplicates while the other fields change per row? > I don’t see duplicates in cqlsh. I've never seen

Re: High read latency

Since you have most of your reads hitting 5-8 SSTables, it's probably related to that increasing your latency. That makes this look like your write workload is either overwrite-heavy or append-heavy. Data for a single partition key is being written to repeatedly over long time periods, and this

Re: To batch or not to batch: A question for fast inserts

ng for your cluster is the factor to focus on and however you > get there is fantastic. more replies inline: > > On Sep 25, 2015, at 1:24 PM, Eric Stevens <migh...@gmail.com> wrote: > > > compaction usually is the limiter for most clusters, so the difference > between asy

Re: To batch or not to batch: A question for fast inserts

ra hops, if you eliminate the > extra hops by token awareness then it just comes down to write size > optimization. > > On Sep 24, 2015, at 5:18 PM, Eric Stevens <migh...@gmail.com> wrote: > > > I side-tracked some punctual benchmarks and stumbled on the > observations

Re: To batch or not to batch: A question for fast inserts

> I side-tracked some punctual benchmarks and stumbled on the observations of unlogged inserts being *A LOT* faster than the async counterparts. My own testing agrees very strongly with this. When this topic came up on this list before, there was a concern that batch coordination produces GC

Re: Inserting null values

...@eventbrite.com wrote: On Wed, Apr 29, 2015 at 9:16 AM, Eric Stevens migh...@gmail.com wrote: In the end, inserting a tombstone into a non-clustered column shouldn't be appreciably worse (if it is at all) than inserting a value instead. Or am I missing something here? There's thresholds (log

Re: Inserting null values

Correct me if I'm wrong, but tombstones are only really problematic if you have them going into clustering keys, then perform a range select on that column, right (assuming it's not a symptom of the antipattern of indefinitely overwriting the same value)? I.E. you're deleting clusters off of a

Re: Inserting null values

Haddad j...@jonhaddad.com wrote: Enough tombstones can inflate the size of an SSTable causing issues during compaction (imagine a multi tb sstable w/ 99% tombstones) even if there's no clustering key defined. Perhaps an edge case, but worth considering. On Wed, Apr 29, 2015 at 9:17 AM Eric

Re: Best Practice to add a node in a Cluster

nodetool repair http://docs.datastax.com/en/cassandra/1.2/cassandra/tools/toolsNodetool_r.html. 2. Wait until repair completes on a node, then move to the next node. Any other things to take care? Thanks Regards neha On Mon, Apr 27, 2015 at 9:45 PM, Eric Stevens migh...@gmail.com

Re: Best Practice to add a node in a Cluster

It depends on why you're adding a new node. If you're running out of disk space or IO capacity in your 2 node cluster, then changing RF to 3 will not improve either condition - you'd still be writing all data to all three nodes. However if you're looking to improve reliability, a 2 node RF=2

Re: Bookstrapping new node isn't pulling schema from cluster

Is it one of your seed nodes, or does it otherwise have itself as a seed? A node will not bootstrap if it is in its own seeds list. On Apr 18, 2015 2:53 PM, Bill Miller bmil...@inthinc.com wrote: I upgraded a 5 node cluster from 1.2.5 to 1.2.9, ran ugradesstables and installed oracle java

Astyanax Thrift Frame Size Hardcoded - Breaks Ring Describe

I know this list isn't the right place to discuss driver issues in general, but I thought I'd offer a word of warning to anyone still using Astyanax related to an issue we ran into over the weekend. Astyanax has a hard coded maximum Thrift frame size. There is a pull request to expose it to

Re: Astyanax Thrift Frame Size Hardcoded - Breaks Ring Describe

to write it off On Apr 3, 2015, at 1:55 PM, Robert Coli rc...@eventbrite.com wrote: On Fri, Apr 3, 2015 at 11:16 AM, Eric Stevens migh...@gmail.com wrote: Astyanax is no longer maintained, so I don't really expect that to go anywhere, which is why I thought it might be a good idea to issue

Re: Replication to second data center with different number of nodes

If you're curious about how Cassandra knows how to replicate data in the remote DC, it's the same as in the local DC, replication is independent in each, and you can even set a different replication strategy per keyspace per datacenter. Nodes in each DC take up num_tokens positions on a ring,

Re: Really high read latency

Enable tracing in cqlsh and see how many sstables are being lifted to satisfy the query (are you repeatedly writing to the same partition [row_time]) over time?). Also watch for whether you're hitting a lot of tombstones (are you deleting lots of values in the same partition over time?). On Mon,

Re: Timeout error in fetching million rows as results using clustering keys

From your description, it sounds like you have a single partition key with millions of clustered values on the same partition. That's a very wide partition. You may very likely be causing a lot of memory pressure in your Cassandra node (especially at 4G) while trying to execute the query.

Re: Is Table created in all the nodes if the default consistency level used

Cassandra is used in a message process system. The table will be created at a fixed time each day. Make sure you're keeping the total number of tables which exist at any given time to a reasonable limit. There is a fixed memory cost for each table, and if you have too many tables you will

Re: CQL 3.x Update ...USING TIMESTAMP...

It's possible, but you'll end up with problems when attempting to overwrite or delete entries I'm wondering if you can elucidate on that a little bit, do you just mean that it's easy to forget to always set your timestamp correctly, and if you goof it up, it makes it difficult to recover from

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