Re: JBOD device space allocation?

If you don't use RandomPartitioner/Murmur3Partitioner you will get the old behavior. On Wed, Feb 24, 2016 at 2:47 AM, Jack Krupansky wrote: > I just wanted to confirm whether my understanding of how JBOD allocates > device space is correct of not... > > Pre-3.2: > On

Re: JBOD device space allocation?

It is mentioned here btw: http://www.datastax.com/dev/blog/improving-jbod On Wed, Feb 24, 2016 at 8:14 AM, Marcus Eriksson wrote: > If you don't use RandomPartitioner/Murmur3Partitioner you will get the old > behavior. > > On Wed, Feb 24, 2016 at 2:47 AM, Jack Krupansky

Re: CRT

Check out http://www.datastax.com/dev/blog/testing-apache-cassandra-with-jepsen. You can run it yourself to test as well. Chris On Tue, Feb 23, 2016 at 7:02 PM, Rakesh Kumar wrote: > https://www.aphyr.com/posts/294-jepsen-cassandra > > How much of this is still valid in ver

Reenable data access after temporarily moving data out of data directory

Hi, I encountered an error in Cassandra or the latest Oracle JVM that causes the JVM to terminate during compaction in my situation (CASSANDRA 11200). In trying work around the problem and access the data , I moved the data eg ma-NNN-big-Filter.db, ma-367-big-Data.db etc. out of the data

Re: Nodes go down periodically

"Is it only one node at a time that goes down, and at widely dispersed times?" It is a two node cluster so both nodes consider the other node down at the same time. These are the times the latest few days: INFO [GossipTasks:1] 2016-02-19 05:06:21,087 Gossiper.java (line 992) InetAddress /x.x.x.x

Cassandra Data Audit

To all Cassandra experts out there, Can you please let me know if there is any inbuilt Cassandra feature that allows audits on Column family data ? When I change any data in a CF, I want to record that change. Probably store the old value as well as the changed one. One way of

JBOD device space allocation?

I just wanted to confirm whether my understanding of how JBOD allocates device space is correct of not... Pre-3.2: On each memtable flush Cassandra will select the directory (device) which has the most available space as a percentage of the total available space on all of the listed

CRT

https://www.aphyr.com/posts/294-jepsen-cassandra How much of this is still valid in ver 3.0. The above seems to have been written for ver 1.0. thanks.

IF NOT EXISTS with multiple static columns confusion

I have a table with 2 static columns, and I write to either one of them, if I then write to the other one using IF NOT EXISTS, it fails even though it has never been written too before. Is it the case that all static columns share the same "written too" marker? Given a table like so: CREATE

Re: copy and rename sstable files as keyspace migration approach

Great info about the Summary.db files, thanks Tyler. On Tue, Feb 23, 2016 at 2:27 PM, Tyler Hobbs wrote: > > On Tue, Feb 23, 2016 at 12:36 PM, Robert Coli > wrote: > >> [1] In some very new versions of Cassandra, this may not be safe to do >> with

Re: copy and rename sstable files as keyspace migration approach

Yes, 1) was just for safety but if cassandra is stopped locally, it's probably not needed. 3) thanks for the note, will add 3) we were thinking of copying, and later (silent 7, as you mentioned, after we drop the old keyspaces\CFs we would delete the original files) 6) good to know! Thanks Rob

Re: copy and rename sstable files as keyspace migration approach

On Tue, Feb 23, 2016 at 12:36 PM, Robert Coli wrote: > [1] In some very new versions of Cassandra, this may not be safe to do > with certain meta information files which are sadly no longer immutable. I presume you're referring to the index summary (i.e Summary.db files).

Re: copy and rename sstable files as keyspace migration approach

On Tue, Feb 23, 2016 at 6:44 AM, Jarod Guertin wrote: > Being fairly new to Cassandra, I'd like to run the following with the > experts to make sure it's an ok thing to do. > > We have a particular case where we have multiple keyspaces with multiple > tables each and

RE: Restart Cassandra automatically

What anti-pattern are you mocking me for exactly? Sean Durity From: daemeon reiydelle [mailto:daeme...@gmail.com] Sent: Tuesday, February 23, 2016 11:21 AM To: user@cassandra.apache.org Subject: RE: Restart Cassandra automatically Cassandra nodes do not go down "for no reason". They are not

Re: „Using Timestamp“ Feature

When using client supplied timestamps you need to ensure the clock on the client is in sync with the nodes in the cluster otherwise behaviour will be unpredictable. On Thu, 18 Feb 2016 at 08:50 Tyler Hobbs wrote: > 2016-02-18 2:00 GMT-06:00 Matthias Niehoff < >

Re: High Bloom filter false ratio

sstablemetadata definitely exists for 2.0 – it may be in a different location, but it exists. If all else fails, it’s a 50 line bash script, grab it from here: https://github.com/apache/cassandra/blob/cassandra-2.0/tools/bin/sstablemetadata From: Anishek Agarwal Reply-To:

Re: Nodes go down periodically

If you can, do a few (short, maybe 10m records, delete the default schema between executions) run of Cassandra Stress test against your production cluster (replication=3, force quorum to 3). Look for latency max in the 10s of SECONDS. If your devops team is running a monitoring tool that looks at

Re: Nodes go down periodically

The reality of modern distributed systems is that connectivity between nodes is never guaranteed and distributed software must be able to cope with occasional absence of connectivity. GC and network connectivity are the two issues that a lot of us are most familiar with. There may be others - but

Re: Restart Cassandra automatically

Hi Subharaj, Cassandra is built to be a Fault tolerant distributed db and suitable for building HA systems. As Cassandra provides multiple replicas for the same data, if a single nide goes down in Production, it wont bring down the cluster. In my opinion, if you target to start one or more

RE: Restart Cassandra automatically

Cassandra nodes do not go down "for no reason". They are not stateless. I would like to thank you for this marvelous example of a wonderful antipattern. Absolutely fantastic. Thank you! I am not being a satirical smartass. I sometimes am challenged by clients in my presentations about sre best

Re: Nodes go down periodically

Hi, Version is 2.0.17. Yes, these are VMs in the cloud though I'm fairly certain they are on a LAN rather than WAN. They are both in the same data centre physically. The phi_convict_threshold is set to default. I'd rather find the root cause of the problem than just hiding it by not convicting a

RE: Restart Cassandra automatically

Yes, I can see the potential problem in theory. However, we never do your #2. Generally, we don’t have unused spare hardware. We just fix the host that is down and run repairs. (Side note: while I have seen nodes fight it out over who owns a particular token in earlier versions, it seems that

RE: Nodes go down periodically

You didn’t mention version, but I saw this kind of thing very often in the 1.1 line. Often this is connected to network flakiness. Are these VMs? In the cloud? Connected over a WAN? You mention that ping seems fine. Take a look at the phi_convict_threshold in c assandra.yaml. You may need to

RE: High Bloom filter false ratio

I see the sstablemetadata tool as far back as 1.2.19 (in tools/bin). Sean Durity From: Anishek Agarwal [mailto:anis...@gmail.com] Sent: Tuesday, February 23, 2016 3:37 AM To: user@cassandra.apache.org Subject: Re: High Bloom filter false ratio Looks like that sstablemetadata is available in 2.2

Re: Nodes go down periodically

Hi, Thanks for your reply. I have debug logging on and see no GC pauses that are that long. GC pauses are all well below 1s and 99 times out of 100 below 100ms. Do I need to enable GC log options to see the pauses? I see plenty of these lines: DEBUG [ScheduledTasks:1] 2016-02-22 10:43:02,891

copy and rename sstable files as keyspace migration approach

Being fairly new to Cassandra, I'd like to run the following with the experts to make sure it's an ok thing to do. We have a particular case where we have multiple keyspaces with multiple tables each and we want to migrate to a new unique keyspace on the same cluster. The approach envisioned is:

Re: Nodes go down periodically

Hi, Those are probably GC pauses. Memory tuning is probably needed. Check the parameters that you already have customised if they make sense. http://blog.mikiobraun.de/2010/08/cassandra-gc-tuning.html Hannu > On 23 Feb 2016, at

Nodes go down periodically

Our nodes go down periodically, around 1-2 times each day. Downtime is from <1 second to 30 or so seconds. INFO [GossipTasks:1] 2016-02-22 10:05:14,896 Gossiper.java (line 992) InetAddress /109.74.13.67 is now DOWN INFO [RequestResponseStage:8844] 2016-02-22 10:05:38,331 Gossiper.java (line 978)

Re: High Bloom filter false ratio

Looks like that sstablemetadata is available in 2.2 , we are on 2.0.x do you know anything that will work on 2.0.x On Tue, Feb 23, 2016 at 1:48 PM, Anishek Agarwal wrote: > Thanks Jeff, Awesome will look at the tools and JMX endpoint. > > our settings are below originated

Re: High Bloom filter false ratio

Thanks Jeff, Awesome will look at the tools and JMX endpoint. our settings are below originated from the jira you posted above as the base. we are running on 48 core machines with 2 SSD disks of 800 GB each . MAX_HEAP_SIZE="6G" HEAP_NEWSIZE="4G" JVM_OPTS="$JVM_OPTS -XX:+UseParNewGC"