RE: Version Upgrade

A related question: Is nodetool upgradesstables only necessary before you’re going to move major versions? I was under the impression that Cassandra N+1 could read the table format of Cassandra N. In other words, if I am running Cassandra 1.2.x and upgrading to 2.0.x, 2.0.x will continue to r

Re: how to start a embed cassandra instance?

dra server. >> >> https://github.com/jsevellec/cassandra-unit this project is good,but the >> license is not suitable. >> how do you achieve this? >> >> thanks in advance >> >> stone >> >> > -- *Ken Hancock *| System Architect, Advanced

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

Until then we have to treat schema delicately. >> >> all the best, >> >> Sebastián >> On Feb 2, 2016 9:48 AM, "Ken Hancock" wrote: >> >>> So this rings odd to me. If you can accomplish the same thing by using >>> a CAS operation, why n

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

>>>> >> >> >> -- >> We’re hiring if you know of any awesome Java Devops or Linux Operations >> Engineers! >> >> Founder/CEO Spinn3r.com >> Location: *San Francisco, CA* >> blog: <http://burtonator.wordpress.com>http://burtonat

Cassandra 1.2 & Compressed Data

We were running a contrived system test last week trying to measure the effect that compaction was having on our I/O and read performance. As a test, we set compaction throughput to 1MB/sec. As expected, we fell greatly behind and the number of SSTables grew. Unexpectedly, we went OOM. One of my

Re: compaction_throughput_mb_per_sec

ughput_mb_per_sec which refers to "across the entire system". node is the predominant term in the yaml configuration, though I can certainly see potential confusion with vnodes. On Tue, Jan 5, 2016 at 2:26 PM, Robert Coli wrote: > On Tue, Jan 5, 2016 at 6:50 AM, Ken Hancock > wro

Re: compaction_throughput_mb_per_sec

documentation lack of clarity issue. On Mon, Jan 4, 2016 at 5:06 PM, Jeff Jirsa wrote: > Why do you think it’s cluster wide? That param is per-node, and you can > change it at runtime with nodetool (or via the JMX interface using jconsole > to ip:7199 ) > > > > From: Ken Hanc

compaction_throughput_mb_per_sec

I was surprised the other day to discover that this was a cluster-wide setting. Why does that make sense? In a heterogeneous cassandra deployment, say I have some old servers running spinning disks and I'm bringing on more nodes that perhaps utilize SSD. I want to have different compaction thro

Re: memtable flush size with LCS

Or if you're doing a high volume of writes, then your flushed file size may be completely determined by other CFs that have consumed the commitlog size, forcing any memtables whose commitlog is being delete to be forced to disk. On Wed, Oct 28, 2015 at 2:51 PM, Jeff Jirsa wrote: > It’s worth men

Re: How to remove huge files with all expired data sooner?

On Mon, Sep 28, 2015 at 2:59 AM, Erick Ramirez wrote: > have many tables like this, and I'd like to reclaim those spaces sooner. > What would be the best way to do it? Should I run "nodetool compact" when I > see two large files that are 2 weeks old? Is there configuration parameters > I can tune

Re: How to run any application on Cassandra cluster in high availability mode

Off-topic to the Cassandra list, but corosync/pacemaker comes to mind for automatic service switchover between nodes. For monitoring and alerting, there's almost too many to mention... On Tue, Aug 18, 2015 at 2:45 PM, Vikram Kone wrote: > Hi John, > I have posted the same Q on azkaban googl

Re: nodetool getendpoints options

There is no difference. In #2, I'm guessing you're confusing using some of the column names as keys. You could also do getendpoints Mykeyspace Mytable 'foo' and Mykeyspace Mytable 'bar' getendpoints does not require any data in your column family to function; it only requires a schema for the co

Re: Hundreds of sstables after every Repair

so many sstables created during repair. When everything is in sync , > why repair creates tiny sstables to repair data? > > Thanks > Anuj Wadehra > > Sent from Yahoo Mail on Android > <https://overview.mail.yahoo.com/mobile/?.src=Android> > -

Re: Hundreds of sstables after every Repair

I think this came up recently in another thread. If you're getting large numbers of SSTables after repairs, that means that your nodes are diverging from the keys that they're supposed to be having. Likely you're dropping mutations. Do a nodetool tpstats on each of your nodes and look at the mut

Re: Drop/Create table with same CF Name

Nate, how does this get around the issue? I'm guessing that just extends the timeout, but if I had a server failure such that the server was down for a couple hours, truncate would still have issues? On Sat, May 23, 2015 at 5:46 PM, Nate McCall wrote: > > > > Truncate would have been the tool

Re: Multiple cassandra instances per physical node

you will >> only have one 1 replica left for some portion of the ring. >> >> >> >> -- >> - >> Nate McCall >> Austin, TX >> @zznate >> >> Co-Founder & Sr. Technical Consultant >> Apache Cassandra Consulting >>

Re: Drop/Create table with same CF Name

for the worlds > most innovative companies such as Netflix, Adobe, Intuit, and eBay. > > > > On Fri, May 22, 2015 at 7:53 AM, Walsh, Stephen > wrote: > > Can someone share the content on this link please, I’m aware of issues > where recreating key spaces can cause inconsisten

Re: Drop/Create table with same CF Name

ntent on this link please, I’m aware of issues > where recreating key spaces can cause inconsistency in 2.0.13 if memTables > are not flushed beforehand , is this the issues that is resolved? > > > > > > *From:* Ken Hancock [mailto:ken.hanc...@schange.com] > *Se

Re: Drop/Create table with same CF Name

rsions-older-than-2-1 > > Mark > > On 21 May 2015 at 15:31, Ken Hancock wrote: > >> >> We've been running into the reused key cache issue (CASSANDRA-5202) with >> dropping and recreating the same table in Cassandra 1.2.18 so we've been >> testing wi

Drop/Create table with same CF Name

We've been running into the reused key cache issue (CASSANDRA-5202) with dropping and recreating the same table in Cassandra 1.2.18 so we've been testing with key caches disabled which does not seem to solve the issue. In the latest logs it seems that old SSTables metadata gets read after the table

Re: Disabling auto snapshots

Is there any method to disable this programmatically on a table-by-table basis. I'm running into an issue regarding drop table which I'll post in a separate thread. On Thu, May 21, 2015 at 3:34 AM, Mark Reddy wrote: > To disable auto snapshots, set the property auto_snapshot: false in your > ca

Re: Updating only modified records (where lastModified < current date)

While updates don't create tombstones, overwrites create a similar performance penalty at the read phase. That key will need to be fetched from every SSTable where it resides so the "most recent" column can be returned. On Wed, May 13, 2015 at 6:38 AM, Peer, Oded wrote: > You can use the “la

Re: Why select returns tombstoned results?

7; 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. >>>

BytesType and UTF8Type

I have some thrift column families that were created with BytesType. All the data written to the keys/columns/values were simple string. In cassandra-cli, I can "correct" these to UTF8Type (I believe both UTF8Type and BytesType are serialized similarly?) but I can't convert these blobs to text vi

Re: Are Triggers in Cassandra 2.1.2 performace Hog??

When last I looked at Datastax Enterprise (DSE 3.0ish), it exhibits the same problem that you highlight, no different than your good idea of asynchronously pushing to ES. Each Cassandra write was indexed independently by each server in the replication group. If a node timed out or a mutation was

Re: 答复:

Architect > > [image: twitter.png] <https://twitter.com/foundev> [image: linkedin.png] > <http://www.linkedin.com/pub/ryan-svihla/12/621/727/> > > DataStax is the fastest, most scalable distributed database technology, > delivering Apache Cassandra to the world’s most

Re: Practical use of counters in the industry

are using Cassandra counters practically. > > Thanks in advance. > > Regards, > Rajath > -------- > Rajath Subramanyam > > -- *Ken Hancock *| System Architect, Advanced Advertising SeaChange International 50 Nagog Park Acton, Massachusetts 01720 ken.hanc

Re: Force purging of tombstones

You can use the JMX forceUserDefinedCompaction operation to compact each SSTable individually. https://github.com/hancockks/cassandra-compact-cf On Sat, Nov 1, 2014 at 11:18 AM, Jens Rantil wrote: > Hi, > > I recently ran a migration where I modified (essentially, deleted and > inserted) a lar

Re: opscenter with community cassandra

ity when >> you cant use it in production. > > > You can use OpsCenter community in production (however you'd like). > > > -- > Tyler Hobbs > DataStax <http://datastax.com/> > > -- *Ken Hancock *| System Architect, Advanced Advertising SeaChange

Re: disk space issue

up the expired data. gc_grace value is set default. I have a >>> replication factor of 3. Do you think that it may help if I delete all data >>> for that node and run repair. Does node repair check the ttl value before >>> retrieving data from other nodes? Do you have any o

Re: Repair taking long time

On Mon, Sep 29, 2014 at 2:29 PM, Robert Coli wrote: > > As an aside, you "just lose" with vnodes and clusters of the size. I > presume you plan to grow over appx 9 nodes per DC, in which case you > probably do want vnodes enabled. > I typically only see discussion on vnodes vs. non-vnodes, but i

Re: Quickly loading C* dataset into memory (row cache)

n wrote: > >> What are you referring to when you say memory store? >> >> RAM disk? memcached? >> > > In 2014, probably Redis? > > =Rob > > -- *Ken Hancock *| System Architect, Advanced Advertising SeaChange International 50 Nagog Park Acton, Massachu

Re: Counters: consistency, atomic batch

> > If it can, do you know which driver supports BEGIN COUNTER BATCH? I > searched the whole source of Astyanax 2.0.1 and it seems that it doesn't > support it currently. > > Thanks in advance! > > PS. Do you know how to communicate with Astyanax team? > I wro

Re: Decommissioning a datacenter deletes the data (on decommissioned datacenter)

decommissioned node itself does not forget its schema, >> which I personally consider a bug.) >> > > > Ok, so I am assuming this is not a normal behavior and possibly a bug - > is this correct ? > > >> >> =Rob >> >> > -- *Ken Hancock *|

Re: Migration from Cassandra 1.2.5 to Cassandra 2.0.8 with changed partitioner settings

ndra cluster just for our application. > > > > > > > > -- > > View this message in context: > > http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Migra > > tion-from-Cassandra-1-2-5-to-Cassandra-2-0-8-with-changed-partitioner- > >

Re: data type is object when metric instrument using Gauge?

datatype of gauge as numeric types >> instead of object, or other way around for example using metric >> reporter...etc? >> >> Thanks a lot for any suggestion! >> >> Best Regard! >> Mike >> >> >> >> > > > -- > P

Re: Hot, large row

> >> 42510 bytes: 48 >> >> 51012 bytes: 21 >> >> 61214 bytes: 15 >> >> 73457 bytes: 10 >> >> 88148 bytes: 3 >> >> 105778 bytes: 4 >> >> 126934 bytes: 1 >> >> 152321 bytes: 2 >> >> 182785 bytes: 1 &

Re: Multi-column range scans

=> (name=140235930:2:, value=, timestamp=1405308260403000) >>>> => (name=140235930:2:skill_count, value=000a, >>>> timestamp=1405308260403000) >>>> => (name=140235930:5:, value=, timestamp=1405308260403001) >>>> => (na

Re: Large SSTable not compacted with size tiered compaction

e to a > sufficiently large value, will the 8.61 GB get compacted? What if any > drawbacks are there to increasing the bucket_high property? > > In what scenarios could I wind up with such a disproportionately large > SSTable like this? One thing that comes to mind is major compa

Re: Controlling system.log rotation

I think this essentially boils down the issue: https://issues.apache.org/bugzilla/show_bug.cgi?id=40407 Seems the best way would be to change the umask for user cassandra: http://stackoverflow.com/questions/7893511/permissions-on-log-files-created-by-log4j-rollingfileappender Ken On Mon, Jul

Re: tracing thrift queries?

ache. > > Tracing them should help iron down whats happening. > > Kevin > > -- > > Founder/CEO Spinn3r.com > Location: *San Francisco, CA* > blog: http://burtonator.wordpress.com > … or check out my Google+ profile > <https://plus.google.com/102718274791889610

Re: RPC timeout paging secondary index query results

You didn't post any timings, only when it started failing so it's unclear whether performance is dropping off or scaling in some sort of linear or non-linear fashion. Second the recommendation to do some traces which should be much more telling. On Fri, Jun 13, 2014 at 3:34 AM, Phil Luckhurst < p

Re: nodetool repair -snapshot option?

>>>> >>>>>> For to record, my view was that this change, which makes repair even >>>>>> slower than it previously was, was probably overly optimistic. >>>>>> >>>>>> It's also weird in that it changes default behavior w

Re: Configuring all nodes as seeds

Amen. I believe the whole seed node/bootstrapping confusion goes against the "Why Cassandra", quoted from http://www.datastax.com/what-we-offer/products-services/datastax-enterprise/apache-cassandra *Operational simplicity* – with all nodes in a cluster being the same, there is no complex configu

Re: Minimum Cluster size to accommodate a single node failure

Another nice resource... http://www.ecyrd.com/cassandracalculator/

Re: Cassanda JVM GC defaults question

nterference and will impact write performance. If you're not > sensitive to this impact, your expectation is correct, however make > sure your flush_largest_memtables_at is always set to less than or > equal to the occupancy fraction. > > On 4/23/14, Ken Hancock wrote: > >

Cassanda JVM GC defaults question

I'm in the process of trying to tune the GC and I'm far from an expert in this area, so hoping someone can tell me I'm either out in left field or on-track. Cassandra's default GC settings are (abbreviated): +UseConcMarkSweepGC +CMSInitiaitingOccupancyFraction=75 +UseCMSInitiatingOccupancyOnly Al

Re: Bootstrap Timing

Should I be concerned? Is there a way to tell how long it will take to >>>> finish? >>>> >>> >>> Adding more than one node at a time to a cluster (especially with >>> vnodes) is Not Supported. If I were you, I would stop all 3 bootstraps and &g

Re: Replication Factor question

Keep in mind if you lose the wrong two, you can't satisfy quorum. In a 5-node cluster with RF=3, it would be impossible to lose 2 nodes without affecting quorum for at least some of your data. In a 6 node cluster, once you've lost one node, if you were to lose another, you only have a 1-in-5 chanc

Re: Intermittent long application pauses on nodes

My searching my list archives shows this thread evaporated. Was a root cause ever found? Very curious. On Mon, Feb 3, 2014 at 11:52 AM, Benedict Elliott Smith < belliottsm...@datastax.com> wrote: > Hi Frank, > > The "9391" under RevokeBias is the number of milliseconds spent > synchronising

Re: Update SSTable fragmentation

s multiple > SSTables? Obviously this has implications for space as a trade off. > > Wayne > > -- *Ken Hancock *| System Architect, Advanced Advertising SeaChange International 50 Nagog Park Acton, Massachusetts 01720 ken.hanc...@schange.com | www.schange.com | NASDAQ:SEAC<

Re: Installing Datastax Cassandra 1.2.15 Using Yum (Java Issue)

On Thu, Mar 27, 2014 at 4:53 PM, Jon Forrest wrote: > It would be great to know the origin of this issue. > > See http://www.rudder-project.org/redmine/issues/2941 for the mess that has been created regarding java JRE dependencies. Ken

Re: Cassandra DSC 2.0.5 not starting - "* could not access pidfile for Cassandra"

epository. > > [0] http://www.datastax.com/documentation/cassandra/2.0/cassandra/install/ > installJreDeb.html > > -- > Kind regards, > Michael > -- *Ken Hancock *| System Architect, Advanced Advertising SeaChange International 50 Nagog Park Acton, Massachusetts 0172

Re: Compaction does not remove tombstones if column has higher TTL

ceptable tradeoff > for me since the 7 day columns are the ones that get much larger (against a > map column type). > > So be warned, mixing TTLs in a row does not appear to result in the data > being compacted away. > > Thanks > -- *Ken Hancock *| System Architect, Ad

Re: Weird timeouts

the number of columns to 0. Without > seeing the row, I have a hard time knowing what could be wrong. Do you have > any ideas? > > > -- *Ken Hancock *| System Architect, Advanced Advertising SeaChange International 50 Nagog Park Acton, Massachusetts 01720 ken.hanc...@schange.com | w

Cassandra-cli and Composite columns

I've been trying to do some simple data modeling and since we're currently using Hector have been doing that modeling with cassandra-cli and running into issues with CompositeType columns. If I do a "help set", I see: The help for "create column family" shows: create column family UseComposites

Re: Opscenter tabs

uot;test", but > change the opscenter tabs to DC1, DC2, and DC3. > >Is this documented somewhere? > > -- > Daniel Curry > Sr Linux Systems Administrator > Arrayent, Inc. > 2317 Broadway Street, Suite 20 > Redwood City, CA 94063 > dan...@arrayent.com > >

Re: MUTATION messages dropped

I've checked the values you indicated. Here they are: > > node1 6498 > node2 6476 > node3 6642 > > I guess this is not good :) What can we do to fix this problem? > > > 2013/12/19 Ken Hancock > >> We had issues where the number of CF familie

Re: MUTATION messages dropped

t;high load" > and what should we tune to make it acceptable? > > Thanks in advance, > Alexander > > [1] http://wiki.apache.org/cassandra/FAQ#dropped_messages > -- *Ken Hancock *| System Architect, Advanced Advertising SeaChange International 50 Nagog Park Acton, Mas

Re: Rowcache and quorum reads cassandra

Cache (you're right about the DC clone so 1/5 of data > instead of 1/10). If however 3 nodes have to be read each time and all 3 > fill up the row cache with the same data that would make my cache > requirements bigger. > > Thanks! > > Artur > > On 10/10/13 14:06,

Re: Rowcache and quorum reads cassandra

of off-heap would be 10 * 3 GB = 30 GB. However is > this still correct with quorum reads? How does cassandra handle row-cache > hits in combination with quorum reads? > > Thanks! > -- artur > -- *Ken Hancock *| System Architect, Advanced Advertising SeaChange Int

Re: Why Solandra stores Solr data in Cassandra ? Isn't solr complete solution ?

indexes will >> be inconsistent with other nodes in its replication group. >> >> Will repair fix it? > -- *Ken Hancock *| System Architect, Advanced Advertising SeaChange International 50 Nagog Park Acton, Massachusetts 01720 ken.hanc...@schange.com | www.schange.com | N

Re: Why Solandra stores Solr data in Cassandra ? Isn't solr complete solution ?

at single machine can > vertically scale, is a single point of failure. > > The value add of DES is that the index has the same availability > characteristics as the underlying data, because it is stored in the same > cluster. > > =Rob > > -- *Ken Hancock *| System A

Re: Among Datastax community & Cassandra debian package, which to choose for production install ?

t; > Btw which is usually preferred for production installs ? > > I may need to use Opscenter but just *occasionally*. > -- *Ken Hancock *| System Architect, Advanced Advertising SeaChange International 50 Nagog Park Acton, Massachusetts 01720 ken.hanc...@schange.com | www.schange.com |

Re: Memtable flush blocking writes

n Mon, Sep 23, 2013 at 6:03 PM, Robert Coli wrote: > On Fri, Aug 23, 2013 at 10:35 AM, Ken Hancock wrote: > >> I appear to have a problem illustrated by >> https://issues.apache.org/jira/browse/CASSANDRA-1955. At low data >> rates, I'm seeing mutation messages dropped b

Re: cassandra just gone..no heap dump, no log info

like running out of memory) >>> >>> Thanks, >>> Dean >>> >> >> >> >> -- >> >> *Franc Carter* | Systems architect | Sirca Ltd >> >> franc.car...@sirca.org.au | www.sirca.org.au >> >> Tel: +61 2 8355

Re: Flush writer all time blocked

ificantly faster than you >> > could flush to disk. >> >> I don't think this is strictly true? There's also the periodic flush >> that can cause a storm of flushes if you have multiple column >> families. I sent out a query to the list last week on thi

Re: Flush writer all time blocked

On Thu, Aug 29, 2013 at 1:57 PM, Robert Coli wrote: > On Thu, Aug 29, 2013 at 10:49 AM, S C wrote: >> I see a high count "All time blocked" for Flush Writer on nodetool tpstats. >> >> Is it how many blocked ever since the server was online? Can somebody >> explain me what it is? I really appreci

Memtable flush blocking writes

I appear to have a problem illustrated by https://issues.apache.org/jira/browse/CASSANDRA-1955. At low data rates, I'm seeing mutation messages dropped because writers are blocked as I get a storm of memtables being flushed. OpsCenter memtables seem to also contribute to this: INFO [OptionalTasks: