Re: CQL Composite Key Seen After Table Creation

On 01/06/2016 04:47 PM, Robert Coli wrote: On Wed, Jan 6, 2016 at 12:54 PM, Chris Burroughs wrote: The problem with that approach is that manually editing the local schema tables in live cluster is wildly dangerous. I *think* this would work: * Make triple sure no schema changes are

Re: CQL Composite Key Seen After Table Creation

I work with Amir and further experimentation I can shed a little more light on what exactly is going on under the hood. For background our goal is to take data that is currently being read and written to via thrift, switch reads to CQL, and then switch writes to CQL. This is in alternative to

Re: Migration 1.2.14 to 2.0.8 causes "Tried to create duplicate hard link" at startup

Were you able to solve or work around this problem? On 06/05/2014 11:47 AM, Tom van den Berge wrote: Hi, I'm trying to migrate a development cluster from 1.2.14 to 2.0.8. When starting up 2.0.8, I'm seeing the following error in the logs: INFO 17:40:25,405 Snapshotting drillster, Account to

Re: Number of rows under one partition key

https://engineering.eventbrite.com/what-version-of-cassandra-should-i-run/ Although by the simplistic version count hueirstic the sheer quantity of releases in the 2.0.x line would now satisfy the constraint. On 05/29/2014 08:08 PM, Paulo Ricardo Motta Gomes wrote: Hey, We are considering up

Re: alternative vnode upgrade strategy?

On 05/28/2014 02:18 PM, William Oberman wrote: 1.) Upgrade all N nodes to vnodes in place Start loop 2.) Boot a new node and let it bootstrap 3.) Decommission an old node End loop I's been a while since I had to think about the vnode migration, but I've think this would fall pray to https://i

Re: New node Unable to gossip with any seeds

This generally means that how you are describing the see nodes address doesn't match how it's described in the second node seeds list in the correct way. CASSANDRA-6523 has some links that might be helpful. On 05/26/2014 12:07 AM, Tim Dunphy wrote: Hello, I am trying to spin up a new node

Re: Is the tarball for a given release in a Maven repository somewhere?

Maven central has "bin.tar.gz" "src.tar.gz" downloads for the 'apache-cassandra' artifact. Does that work for your use case? http://search.maven.org/#search%7Cga%7C1%7Ca%3A%22apache-cassandra%22 On 05/20/2014 05:30 PM, Clint Kelly wrote: Hi all, I am using the maven assembly plugin to build

Re: Backup procedure

It's also good to note that only the Data files are compressed already. Depending on your data the Index and other files may be a significant percent of total on disk data. On 05/02/2014 01:14 PM, tommaso barbugli wrote: In my tests compressing with lzop sstables (with cassandra compression t

Re: What does the "rate" signify for latency in the JMX Metrics?

They are exponential decaying moving averages (like Unix load averages) of the number of events per unit of time. http://wiki.apache.org/cassandra/Metrics might help On 04/17/2014 06:06 PM, Redmumba wrote: Good afternoon, I'm attempting to integrate the metrics generated via JMX into our inte

Re: row caching for frequently updated column

You are close. On 04/30/2014 12:41 AM, Jimmy Lin wrote: thanks all for the pointers. let' me see if I can put the sequences of event together 1.2 people mis-understand/mis-use row cache, that cassandra cached the entire row of data even if you are only looking for small subset of the row

Re: mixed nodes, some SSD some HD

No. If you have a heterogeneous clusters you should consider adjusting the number of vnodes per physical node. On 03/04/2014 10:47 PM, Elliot Finley wrote: Using Cassandra 2.0.x If I have a 3 node cluster and 2 of the nodes use spinning drives and 1 of them uses SSD, will the majority of the

Re: Thrift Server Implementations

On 02/13/2014 01:37 PM, Christopher Wirt wrote: Anyway, today I moved the old HsHa implementation and the new TThreadSelectorServer into a 2.0.5 checkout, hooked them in, built, did a bit of testing and I'm now running live. We found the TThreadSelectorServer performed the best getting us back

Re: ring describe returns only public ips

More generally, a thrift api or other mechanism for Astyanax to get the INTERNAL_IP seems necessary to use ConnectionPoolType.TOKEN_AWARE + NodeDiscoveryType.TOKEN_AWARE in a multi-dc setup. Absent one I'm confused how that combination is possible. On 02/06/2014 03:17 PM, Ted Pearson wrote:

Re: First SSTable file is not being compacted

b). However, in OpsCenter the CF: SSTable Count (demodb.users) graph shows only one SSTable. The nodetool cfstats command also shows "SSTable count: 1" for this CF. - SF On Thu, Feb 6, 2014 at 8:54 AM, Chris Burroughs wrote: On 02/06/2014 01:17 AM, Sameer Farooqui wrote: I'm runn

Re: First SSTable file is not being compacted

On 02/06/2014 01:17 AM, Sameer Farooqui wrote: I'm running C* 2.0.4 and when I have a handful of SSTable files and trigger a manual compaction with 'nodetool compact' the first SSTable file doesn't get compacted away. Is there something special about the first SSTable that it remains even after

Re: what tool will create noncql columnfamilies in cassandra 3a

On 02/05/2014 04:57 AM, Sylvain Lebresne wrote: >How will users adjust the meta data of non cql column families The rational for removing cassandra-cli is mainly that maintaining 2 fully featured command line interface is a waste of the project resources in the long run. It's just a tool using t

Re: Question about local reads with multiple data centers

On 01/29/2014 08:07 PM, Donald Smith wrote: My question: will the read process try to read first locally from the datacenter DC2 I specified in its connection string? I presume so. (I doubt that it uses the client's IP address to decide which datacenter is closer. And I am unaware of anot

Re: Question: ConsistencyLevel.ONE with multiple datacenters

I think the scenario you outlined is correct. The DES handles multiple DCs poorly and the LOCAL_ONE hammer is the best bet. On 01/31/2014 12:40 PM, Paulo Ricardo Motta Gomes wrote: Hey, When adding a new data center to our production C* datacenter using the procedure described in [1], some of

Re: Row cache vs. OS buffer cache

My experience has been that the row cache is much more effective. However, reasonable row cache sizes are so small relative to RAM that I don't see it as a significant trade-off unless it's in a very memory constrained environment. If you want to enable the row cache (a big if) you probably wa

Re: nodetool cleanup / TTL

On 01/07/2014 01:38 PM, Tyler Hobbs wrote: On Tue, Jan 7, 2014 at 7:49 AM, Chris Burroughs wrote: This has not reached a consensus in #cassandra in the past. Does `nodetool cleanup` also remove data that has expired from a TTL? No, cleanup only removes rows that the node is not a replica

nodetool cleanup / TTL

This has not reached a consensus in #cassandra in the past. Does `nodetool cleanup` also remove data that has expired from a TTL?

Re: vnode in production

On 01/06/2014 01:56 PM, Arindam Barua wrote: Thanks for your responses. We are on 1.2.12 currently. The fixes in 1.2.13 seem to help for clusters in the 500+ node range (like CASSANDRA-6409). Ours is below 50 now, so we plan to go ahead and enable vnodes with the 'add a new DC' procedure. We wi

Re: vnode in production

On 01/02/2014 01:51 PM, Arindam Barua wrote: 1. the stability of vnodes in production I'm happily using vnodes in production now, but I would have trouble calling them stable for more than small clusters until very recently (1.2.13). CASSANDRA-6127 served as a master ticket for most of

Re: How to measure data transfer between data centers?

https://wiki.apache.org/cassandra/Metrics has per node Streaming metrics that include total bytes/in out. That is only a small bit of what you want though. For total DC bandwidth it might be more straightforward to measure this at the router/switch/fancy-network-gear level. On 12/03/2013 06

MiscStage Backup

I'm trying to debug a node that has a backup in MiscStage. Starting a bit under 24 hours ago the number of Pending tasks jumped to a bit under 400 and hovered around there. It looks like repair requests from other nodes (tpstats on this node shows AntiEntropySessions: 0, 0, 0, which I think

Re: Cassandra 1.1.6 - New node bootstrap not completing

On 11/01/2013 03:03 PM, Robert Coli wrote: On Fri, Nov 1, 2013 at 9:36 AM, Narendra Sharma wrote: I was successfully able to bootstrap the node. The issue was RF > 2. Thanks again Robert. For the record, I'm not entirely clear why bootstrapping two nodes into the same range should have cause

Re: Why truncate previous hints when upgrade from 1.1.9 to 1.2.6?

NEWS.txt has some details and suggested procedures - The hints schema was changed from 1.1 to 1.2. Cassandra automatically snapshots and then truncates the hints column family as part of starting up 1.2 for the first time. Additionally, upgraded nodes will not store new hin

Re: Endless loop LCS compaction

On 11/07/2013 06:48 AM, Desimpel, Ignace wrote: Total data size is only 3.5GB. Column family was created with SSTableSize : 10 MB You may want to try a significantly larger size. https://issues.apache.org/jira/browse/CASSANDRA-5727

Re: Cass 2.0.0: Extensive memory allocation when row_cache enabled

On 11/06/2013 11:18 PM, Aaron Morton wrote: The default row cache is of the JVM heap, have you changed to the ConcurrentLinkedHashCacheProvider ? ConcurrentLinkedHashCacheProvider was removed in 2.0.x.

Re: Cass 2.0.0: Extensive memory allocation when row_cache enabled

Both caches involve several objects per entry (What do we want? Packed objects. When do we want them? Now!). The "size" is an estimate of the off heap values only and not the total size nor number of entries. An acceptable size will depend on your data and access patterns. In one case we h

Re: [RELEASE] Apache Cassandra 2.0.2 released

On 10/28/2013 06:20 AM, Sylvain Lebresne wrote: [2]:http://goo.gl/uEtkmb (NEWS.txt) https://wiki.apache.org/cassandra/Metrics has been updated with a reference to the new Configurable metrics reporting.

Re: How to use Cassandra on-node storage engine only?

As far as I know this had not been done before. I would be interested in hearing how it turned out. On 10/23/2013 09:47 AM, Yasin Celik wrote: I am developing an application for data storage. All the replication, routing and data retrieving types of business are handled in my application.

Re: Huge multi-data center latencies

On 10/21/2013 07:03 PM, Hobin Yoon wrote: Another question is how do you get the local DC name? Have a look at org.apache.cassandra.db.EndpointSnitchInfo.getDatacenter

Re: nodetool status reporting dead node as UN

When debugging gossip related problems (is this node really down/dead/some-werid state) you might have better luck looking at `nodetool gossipinfo`. The "UN even though everything is bad thing" might be https://issues.apache.org/jira/browse/CASSANDRA-5913 I'm not sure what exactly what happen

Re: The performance difference of online bulk insertion and the file-based bulk loading

On 10/15/2013 08:41 AM, José Elias Queiroga da Costa Araújo wrote: - is that is there a way that we can warm-up the cache, after the file-based bulk loading, so that we can allow the data to be cached first in the memory, and then afterwards, when we issue the bulk retrieval, the performance can

vnode + multi dc migration

I know there is a good deal of interest [1] on feasible methods for enabling vnodes on clusters that did not start with them. We recently completed a migration from a production cluster not using vnodes and in a single DC to one using vnodes in two DCs. We used the "just spin up a new DC and

Re: Multi-dc restart impact

Thanks, double checked; reads are CL.ONE. On 10/10/2013 11:15 AM, J. Ryan Earl wrote: Are you doing QUORUM reads instead of LOCAL_QUORUM reads? On Wed, Oct 9, 2013 at 7:41 PM, Chris Burroughs wrote: I have not been able to do the test with the 2nd cluster, but have been given a disturbing

Re: Multi-dc restart impact

5ymL.png?1 * perf in other DC: http://i.imgur.com/gEMrLyF.png?1 Not only was a single slow node able to cause an order of magnitude performance hit in a dc, but the other dc faired *worse*. On 09/18/2013 08:50 AM, Chris Burroughs wrote: On 09/17/2013 04:44 PM, Robert Coli wrote: On Thu, Sep 5,

gossip settling and bootstrap problems

I've been running into a variety of tricky to diagnose problems recently that could be summarized as "bootstrap & related tasks fail without extra hacky sleep time". This is a sample edited log file for bootstrapping a node that captures the general dynamics: http://pastebin.com/yeN9USLt This

Re: Nodes separating from the ring

I have observed one problem with an inconsistent ring that is superficially similar (node thinks it's up but peers disagree) and noted details in CASSANDRA-6082. However, it does not sound like the details of either the symptoms, or the resolution match what you describe. If you have not alre

Re: I don't understand shuffle progress

finishes I can remove the original. Any good resource that explains how to add a new datacenter to a live single dc cluster that anybody can recommend? On Wed, Sep 18, 2013 at 9:58 AM, Chris Burroughs wrote: On 09/17/2013 09:41 PM, Paulo Motta wrote: So you're saying the only feasible w

Re: I don't understand shuffle progress

On 09/17/2013 09:41 PM, Paulo Motta wrote: So you're saying the only feasible way of enabling VNodes on an upgraded C* 1.2 is by doing fork writes to a brand new cluster + bulk load of sstables from the old cluster? Or is it possible to succeed on shuffling, even if that means waiting some weeks

Re: Multi-dc restart impact

On 09/17/2013 04:44 PM, Robert Coli wrote: On Thu, Sep 5, 2013 at 6:14 AM, Chris Burroughs wrote: We have a 2 DC cluster running cassandra 1.2.9. They are in actual physically separate DCs on opposite coasts of the US, not just logical ones. The primary use of this cluster is CL.ONE reads

Multi-dc restart impact

We have a 2 DC cluster running cassandra 1.2.9. They are in actual physically separate DCs on opposite coasts of the US, not just logical ones. The primary use of this cluster is CL.ONE reads out of a single column family. My expectation was that in such a scenario restarts would have minima

Re: row cache

On 09/01/2013 03:06 PM, Faraaz Sareshwala wrote: Yes, that is correct. The SerializingCacheProvider stores row cache contents off heap. I believe you need JNA enabled for this though. Someone please correct me if I am wrong here. The ConcurrentLinkedHashCacheProvider stores row cache contents o

multi-dc clusters with 'local' ips and no vpn

Cassandra makes the totally reasonable assumption that the entire cluster is in one routable address space. We unfortunately had a situation where: * nodes can talk to each other in the same dc on an internal address, but not talk to each other over their external 1:1 NAT address. * nodes can ta

Cassandra DC Meetup: Cassandra on flash storage

http://www.meetup.com/Cassandra-DC-Meetup/events/104345302/ This month we will have a presentation by our very own Matt Kennedy about running Cassandra on super fancy flash. If you are in the DC are we would love to see you stop by.

SurgeCon 2012

Surge [1] is scalability focused conference in late September hosted in Baltimore. It's a pretty cool conference with a good mix of operationally minded people interested in scalability, distributed systems, systems level performance and good stuff like that. You should go! [2] For those of you

Re: Distinct Counter Proposal for Cassandra

Well I obviously think it would be handy. If this get's proposed and end's up using stream-lib don't be shy about asking for help. On a more general note, it would be great to see the special case Counter code become more general atomic operation code. On 06/13/2012 01:15 PM, Utku Can Topçu wrot

Re: Distinct Counter Proposal for Cassandra

On 06/13/2012 01:00 PM, Yuki Morishita wrote: > The above implementation and most of the other ones (including stream-lib) > implement the optimized version of the algorithm which counts up to 10^9, so > may need some work. > > Other alternative is self-learning bitmap > (http://ect.bell-labs.c

Re: Row caching in Cassandra 1.1 by column family

Check out the "rows_cached" CF attribute. On 06/18/2012 06:01 PM, Oleg Dulin wrote: > Dear distinguished colleagues: > > I don't want all of my CFs cached, but one in particular I do. > > How can I configure that ? > > Thanks, > Oleg >

Re: 1.0.3 CLI oddities

Sounds like https://issues.apache.org/jira/browse/CASSANDRA-3558 and the other tickets reference there. On 11/28/2011 05:05 AM, Janne Jalkanen wrote: > Hi! > > (Asked this on IRC too, but didn't get anyone to respond, so here goes...) > > Is it just me, or are these real bugs? > > On 1.0.3, fr

Re: Second Cassandra users survey

- It would be super cool if all of that counter work made it possible to support other atomic data types (sets? CAS? just pass a assoc/commun Function to apply). - Again with types, pluggable type specific compression. - Wishy washy wish: Simpler "elasticity" I would like to go from 6-->8-->7

Re: CMS GC initial-mark taking 6 seconds , bad?

On 10/20/2011 09:38 AM, Maxim Potekhin wrote: > I happen to have 48GB on each machines I use in the cluster. Can I > assume that I can't really use all of this memory productively? Do you > have any suggestion related to that? Can I run more than one instance on > Cassandra on the same box (using d

Re: ApacheCon meetup?

On 10/11/2011 12:05 PM, Eric Evans wrote: > Let's do it. We can organize an official one, and still grab food > together if that's not enough. :) Great! Thanks for putting this together.

ApacheCon meetup?

ApacheCon NA is coming up next month. I suspect there will be at least a few Cassandra users there (yeah new release!). Would anyone be interested in getting together and sharing some stories? This could either be a "official" [1] meetup. Or grabbing food together sometime. [1] http://wiki.apa

Re: Surgecon Meetup?

On 09/25/2011 07:27 PM, Chris Burroughs wrote: > Surge [1] is scalability focused conference in late September hosted in > Baltimore. It's a pretty cool conference with a good mix of > operationally minded people interested in scalability, distributed > systems, systems level perf

Surgecon Meetup?

Surge [1] is scalability focused conference in late September hosted in Baltimore. It's a pretty cool conference with a good mix of operationally minded people interested in scalability, distributed systems, systems level performance and good stuff like that. You should go! [2] Anyway, I'll be t

Re: Survey: Cassandra/JVM Resident Set Size increase

iew_bug.do?bug_id=7066129) is the culprit. On 07/12/2011 09:28 AM, Chris Burroughs wrote: > ### Preamble > > There have been several reports on the mailing list of the JVM running > Cassandra using "too much" memory. That is, the resident set size is >>> (max java heap

Re: cassandra server disk full

On 07/25/2011 01:53 PM, Ryan King wrote: > Actually I was wrong– our patch will disable gosisp and thrift but > leave the process running: > > https://issues.apache.org/jira/browse/CASSANDRA-2118 > > If people are interested in that I can make sure its up to date with > our latest version. Thank

Re: JNA to avoid swap but physical memory increase

On 07/15/2011 07:24 AM, Daniel Doubleday wrote: > Also our experience shows that the jna call does not prevent swapping so the > general advice is disable swap. Can you confirm you don't get the (paraphrasing) "whoops we tried mlockall but ulimits denied us" message on startup?

Re: Storing counters in the standard column families along with non-counter columns ?

On 07/13/2011 03:57 PM, Aaron Morton wrote: > You can always use a dedicated CF for the counters, and use the same row key. Of course one could do this. The problem is you are now spending ~2x disk space on row keys, and app specific client code just became more complicated.

Survey: Cassandra/JVM Resident Set Size increase

### Preamble There have been several reports on the mailing list of the JVM running Cassandra using "too much" memory. That is, the resident set size is >>(max java heap size + mmaped segments) and continues to grow until the process swaps, kernel oom killer comes along, or performance just degra

Re: Storing counters in the standard column families along with non-counter columns ?

On 07/10/2011 01:09 PM, Aditya Narayan wrote: > Is there any target version in near future for which this has been promised > ? The ticket is problematic in that it would -- unless someone has a clever new idea -- require breaking thrift compatibility to add it to the api. Since is unfortunate si

Re: Cassandra DC Upcoming Meetup

On 06/15/2011 08:57 AM, Chris Burroughs wrote: > Cassandra DC's first meetup of the pizza and talks variety will be on > July 6th. There will be an introductory sort of presentation and a > totally cool one on Pig integration. > > If you are in the DC area it would be gr

Re: 99.999% uptime - Operations Best Practices?

On 06/23/2011 01:56 PM, Les Hazlewood wrote: > Is there a roadmap or time to 1.0? Even a ballpark time (e.g next year 3rd > quarter, end of year, etc) would be great as it would help me understand > where it may lie in relation to my production rollout. The C* devs are rather strongly inclined a

Re: 99.999% uptime - Operations Best Practices?

On 06/23/2011 02:00 PM, Les Hazlewood wrote: > This leads me to believe that Cassandra may not be a good idea for a primary > OLTP data store. For example "only create a user object if email foo is not > already in use" or, more generally, "you can't create object X because one > with an existing

Re: 99.999% uptime - Operations Best Practices?

On 06/22/2011 07:12 PM, Les Hazlewood wrote: > Telling me to read the mailing lists and follow the issue tracker and use > monitoring software is all great and fine - and I do all of these things > today already - but this is a philosophical recommendation that does not > actually address my questi

Re: 99.999% uptime - Operations Best Practices?

On 06/22/2011 10:03 PM, Edward Capriolo wrote: > I have not read the original thread concerning the problem you mentioned. > One way to avoid OOM is large amounts of RAM :) On a more serious note most > OOM's are caused by setting caches or memtables too large. If the OOM was > caused by a software

Re: OOM (or, what settings to use on AWS large?)

ap do what it did ...and the buffered/cached seems > much better > > -sd > > On Thu, Jun 23, 2011 at 12:09 AM, Chris Burroughs > wrote: >> >> In `free` terms, by pegged do you mean that free "Mem" was 0, or "-/+ >> buffers/cache" as 0?

Re: 99.999% uptime - Operations Best Practices?

On 06/22/2011 05:33 PM, Les Hazlewood wrote: > Just to be clear: > > I understand that resources like [1] and [2] exist, and I've read them. I'm > just wondering if there are any 'gotchas' that might be missing from that > documentation that should be considered and if there are any recommendatio

Re: OOM (or, what settings to use on AWS large?)

On 06/22/2011 08:53 AM, Sasha Dolgy wrote: > Yes ... this is because it was the OS that killed the process, and > wasn't related to Cassandra "crashing". Reviewing our monitoring, we > saw that memory utilization was pegged at 100% for days and days > before it was finally killed because 'apt' was

Re: BloomFilterFalsePositives equals 1.0

To be precise, you made n requests for non-existent keys, got n negative responses, and BloomFilterFalsePositives also went up by n? On 06/21/2011 11:06 PM, Preston Chang wrote: > Hi,all: > I have a problem with bloom filter. When made a test which tried to get > some nonexistent keys, it see

Cassandra DC Upcoming Meetup

Cassandra DC's first meetup of the pizza and talks variety will be on July 6th. There will be an introductory sort of presentation and a totally cool one on Pig integration. If you are in the DC area it would be great to see you there. http://www.meetup.com/Cassandra-DC-Meetup/events/22145481/

Re: Data directories

On 06/08/2011 05:54 AM, Héctor Izquierdo Seliva wrote: > Is there a way to control what sstables go to what data directory? I > have a fast but space limited ssd, and a way slower raid, and i'd like > to put latency sensitive data into the ssd and leave the other data in > the raid. Is this possibl

Re: Index interval tuning

On 05/10/2011 10:24 PM, aaron morton wrote: > What version and what were the values for RecentBloomFilterFalsePositives and > BloomFilterFalsePositives ? > > The bloom filter metrics are updated in SSTableReader.getPosition() the only > slightly odd thing I can see is that we do not count a key

Re: Index interval tuning

On 05/10/2011 02:12 PM, Peter Schuller wrote: >> That reminds me, my false positive ration is stuck at 1.0, so I guess >> bloom filters aren't doing a lot for me. > > That sounds unlikely unless you're hitting some edge case like reading > a particular row that happened to be a collision, and only

Re: Native heap leaks?

On 2011-05-05 06:30, Hannes Schmidt wrote: > This was my first thought, too. We switched to mmap_index_only and > didn't see any change in behavior. Looking at the smaps file attached > to my original post, one can see that the mmapped index files take up > only a minuscule part of RSS. I have not

Cassandra Meetup in DC

http://www.meetup.com/Cassandra-DC-Meetup/ *What*: First Cassandra DC Meetup *When*: Thursday, May 12, 2011 at 6:30 PM *Where*: Northside Social Coffee & Wine - 3211 Wilson Blvd Arlington, VA I'm pleased to announce the the first Cassandra DC Meetup

flashcache experimentation

https://github.com/facebook/flashcache/ "FlashCache is a general purpose writeback block cache for Linux." We have a case where: - Access to data is not uniformly random (let's say Zipfian). - The "hot" set > RAM. - Size of disk is such that buying enough SSDs, fast drives, multiple drives, et

Re: quick repair tool question

On 04/12/2011 11:11 AM, Jonathan Colby wrote: > I'm not sure if this is the "kosher" way to rebuild the sstable data, but it > seemed to work. http://wiki.apache.org/cassandra/Operations#Handling_failure Option #3.

Re: CL.ONE reads / RR / badness_threshold interaction

On 04/12/2011 06:27 PM, Peter Schuller wrote: >> So to increase pinny-ness I'll further reduce RR chance and set a >> badness threshold. Thanks all. > > Just be aware that, assuming I am not missing something, while this > will indeed give you better cache locality under normal circumstances > -

Analysing hotspot gc logs

To avoid taking my own thread [1] off on a tangent. Does anyone have a reccomendation for a tool to graphical analysis (ie make useful graphs) out of hoptspot gc logs? Google searches have turned up several results along the lines of "go try this zip file" [2]. [1] http://www.mail-archive.com/us

Re: Minor Follow-up: reduced cached mem; resident set size growth

On 04/05/2011 03:04 PM, Chris Burroughs wrote: > I have gc logs if anyone is interested. This is from a node with standard io, jna enabled, but limits were not set for mlockall to succeed. One can see -/+ buffers/cache free shrinking and the C* pid's RSS growing. Includes several day

Re: CL.ONE reads / RR / badness_threshold interaction

Peter, thank you for the extremely detailed reply. To now answer my own question, the critical points that are different from what I said earlier are: that CL.ONE does prefer *one* node (which one depending on snitch) and that RR uses digests (which are not mentioned on the wiki page [1]) instead

CL.ONE reads / RR / badness_threshold interaction

My understanding for For CL.ONE. For the node that receives the request: (A) If RR is enabled and this node contains the needed row --> return immediately and do RR to remaining replicas in background. (B) If RR is off and this node contains the needed row --> return the needed data immediately.

Re: Minor Follow-up: reduced cached mem; resident set size growth

On 04/05/2011 04:38 PM, Peter Schuller wrote: >> - Different collectors: -XX:+UseParallelGC -XX:+UseParallelOldGC > > Unless you also removed the -XX:+UseConcMarkSweepGC I *think* it takes > precedence, so that the above options would have no effect. I didn't > test. In either case, did you defini

Minor Follow-up: reduced cached mem; resident set size growth

This is a minor followup to this thread which includes required context: http://www.mail-archive.com/user@cassandra.apache.org/msg09279.html I haven't solved the problem, but since negative results can also be useful I thought I would share them. Things I tried unsuccessfully (on individual node

Re: IndexInterval Tuning

On 04/05/2011 09:57 AM, Jonathan Ellis wrote: > On Tue, Apr 5, 2011 at 8:54 AM, Jonathan Ellis wrote: >> Adjusting indexinterval is unlikely to be useful on very narrow rows. >> (Its purpose is to make random access to _large_ rows doable.) > > Whoops, that's column_index_size_in_kb. > > I'd pla

IndexInterval Tuning

I have a case with very narrow rows. As such I have a large row cache that does nicely handles > 50% of requests. I think it's likely that the current tradeoff between page cache and row cache is reasonable. Using a key cache doesn't make sense in this instance. However, a third option is to adj

Re: How to determine if repair need to be run

On 03/29/2011 01:18 PM, Peter Schuller wrote: > (What *would* be useful perhaps is to be able to ask a node for the > time of its most recently started repair, to facilitate easier > comparison with GCGraceSeconds for monitoring purposes.) I concur. JIRA time? (Perhaps keeping track of the same

Re: On 0.6.6 to 0.7.3 migration, DC-aware traffic and minimising data transfer

On 03/11/2011 03:46 PM, Jonathan Ellis wrote: > Repairs is not yet WAN-optimized but is still cheap if your replicas > are close to consistent since only merkle trees + inconsistent ranges > are sent over the network. > What is the ticket number for WAN optimized repair?

Re: memory utilization

On 03/10/2011 09:26 PM, Bill Hastings wrote: > Hi All > > Memory utilization reported by JCOnsole for Cassandra seems to be much > lesser than that reported by top ("RES" memory). Can someone explain this? > Maybe off topic but would appreciate a response. > Is there an more or less constant amo

Re: Reducing memory footprint

On 03/04/2011 03:51 PM, Casey Deccio wrote: > Are you saying: that you want a smaller heap and what settings to change >> to accommodate that, or that you have already set a small heap of x and >> Cassandra is using significantly more than that? >> > > Based on my observation above, the latter. >

Re: cassandra in-production experiences with .7 series

On 03/05/2011 05:27 PM, Paul Pak wrote: > Hello all, > > I was wondering if people could share their overall experiences with > using .7 series of Cassandra in production? Is anyone using it? > For what it's worth we are using a dozen node 0.7.x cluster have not had any major problems (our uses

Re: OOM exceptions

? On 03/04/2011 03:25 PM, Mark wrote: > This happens during compaction and we are not using the RowsCached > attribute. > > Our initial/max heap are 2 and 6 respectively and we have 8 gigs in > these machines. > > Thanks > > On 3/4/11 12:05 PM, Chris Burroughs wrote

Re: OOM exceptions

See also: http://www.datastax.com/docs/0.7/troubleshooting/index#nodes-are-dying-with-oom-errors On 03/04/2011 03:05 PM, Chris Burroughs wrote: > - Does this occur only during compaction or at seemingly random times? > - How large is your heap? What jvm settings are you using? Ho

Re: OOM exceptions

- Does this occur only during compaction or at seemingly random times? - How large is your heap? What jvm settings are you using? How much physical RAM do you have? - Do you have the row and/or key cache enabled? How are they configured? How large are they when the OOM is thrown? On 03/04/2011

Re: Reducing memory footprint

On 03/04/2011 01:53 PM, Casey Deccio wrote: > I have a small ring of cassandra nodes that have somewhat limited memory > capacity for the moment. Cassandra is eating up all the memory on these > nodes. I'm not sure where to look first in terms of reducing the foot > print. Keys cached? Compacti

Re: Column name size

On 02/11/2011 05:06 AM, Patrik Modesto wrote: > Hi all! > > I'm thinking if size of a column name could matter for a large dataset > in Cassandra (I mean lots of rows). For example what if I have a row > with 10 columns each has 10 bytes value and 10 bytes name. Do I have > half the row size just

  1   2   >