Hi all,
We have a 3 node cluster setup, single keyspace, about 500 tables. The
hardware is 2 cores + 16 GB RAM (Cassandra chose to have 4GB). Cassandra
version is 2.0.3. Our replication factor is 3, read/write consistency is
QUORUM. We've plugged it into our production environment as a cache in
Hi,
We currently have a 28 node C* cluster on m1.XLarge instances using Vnodes
and are encountering a Raid issue with one of them.
The first solution could be to decommission this node and insert a new one
in the cluster, since we use vnodes we need to run 28 cleanup after adding
a node, this
Hi again,
I have much more in formations on this case :
We did further investigations on the nodes affected and did find some await
problems on one of the 4 disk in raid:
http://imageshack.com/a/img824/2391/s7q3.jpg
Here was the iostat of the node :
I want to build a really simple column family which counts the occurrence of
a single event X.
Once we reach Y occurrences of X the counter resets to 0
The obvious way to do this is with a counter CF.
CREATE TABLE xcounter1 (
id uuid,
someid int,
How many distinct uid,someid pairs will you have?
On Dec 5, 2013 3:44 PM, Christopher Wirt chris.w...@struq.com wrote:
I want to build a really simple column family which counts the occurrence
of a single event X.
Once we reach Y occurrences of X the counter resets to 0
The obvious way
Some big systems using Cassandra's counters were built (such as Rainbird:
http://www.slideshare.net/kevinweil/rainbird-realtime-analytics-at-twitter-strata-2011)
and seem to be doing great job.
If you are concerned with performance, then maybe using memory-based store
(such as Redis) will better
We just migrated a Cassandra cluster on EC2 to another instance type. We
replaced one server after another, this creates problems similar to what
you describe.
We simply stop Cassandra, copy the complete data dir to an EBS volume,
terminate the server, launch another server with the same IP,
Do you mean high CPU usage or high load avg? (20 indicates load avg to
me). High load avg means the CPU is waiting on something.
Check iostat -dmx 1 100 to check your disk stats, you'll see the columns
that indicate mb/s read write as well as % utilization.
Once you understand the bottleneck
Hi Andy,
There will be 10's millions of uid each with 100's of someid being accessed
each day.
Hi Przemek,
We currently use counter column families, but they are some of our slowest.
(they are also some of our biggest, so the counter type might not be the
issue)
We have a strong need
Hi,
I study cassandra and want to play with it.
I need to shrink the number of
available row instances.
Next send a search request for it in cqlsh with different consistency
levels.
To observe behavior I need to know which instance to take down.
I found cassandra-cli command list.
this
On Thu, Dec 5, 2013 at 9:58 AM, Daneel Yaitskov rtfm.rtfm.r...@gmail.comwrote:
The best solution would be get IP address (node UUID) directly by a human
readable structured row key.
nodetool getendpoints
exposes a JMX endpoint which does that. I'm not clear on whether that is
sufficient for
On Thu, Dec 5, 2013 at 4:33 AM, Alexander Shutyaev shuty...@gmail.comwrote:
Cassandra version is 2.0.3. ... We've plugged it into our production
environment as a cache in front of postgres.
https://engineering.eventbrite.com/what-version-of-cassandra-should-i-run/
What can be the reason?
When running Cassandra from trunk/master, I see a drop keyspace command hang
at the CQL prompt.
To reproduce:
1) Removed my cassandra data directory entirely
2) Fired up cqlsh, and executed the following CQL commands in succession:
bone@zen:~/git/boneill42/cassandra- bin/cqlsh
Connected to Test
I've recently pushed up a new project to github, which we've named Under
Siege. It's a java agent for reporting Cassandra metrics to statsd. We've
in the process of deploying it to our production clusters. Tested against
Cassandra 1.2.11. The metrics library seems to change on every release of
On Thu, Dec 5, 2013 at 8:31 AM, Andre Sprenger andre.spren...@getanet.dewrote:
We just migrated a Cassandra cluster on EC2 to another instance type. We
replaced one server after another, this creates problems similar to what
you describe.
We simply stop Cassandra, copy the complete data dir
Per the 256mb to 5mb change, check the very last section of this page:
http://www.datastax.com/documentation/cql/3.0/webhelp/cql/cql_reference/alter_table_r.html
Changing any compaction or compression option erases all previous
compaction or compression settings.
In other words, you have to
Hello everybody!
We run cassandra 1.1 on ec2 instances. We use three availability zones, the
replication factor is 3 also. NetworkTopologyStrategy guarantees each row
is replicated in all availability zones. So, if we lost one zone quorum
operations still work. We think about to upgrade to 1.2.
Hey Brian, just out of curiosity, why would you remove cassandra data
directory entirely?
/Jason
On Fri, Dec 6, 2013 at 2:38 AM, Brian O'Neill b...@alumni.brown.edu wrote:
When running Cassandra from trunk/master, I see a drop keyspace command hang
at the CQL prompt.
To reproduce:
1)
I removed the data directory just to make sure I had a clean environment.
(eliminating the possibility of corrupt keyspaces/files causing problems)
-brian
---
Brian O'Neill
Chief Architect
Health Market Science
The Science of Better Results
2700 Horizon Drive King of Prussia, PA 19406
M:
Availability zones are analogous to racks not data centres . EC2 regions
are equivalent to data centres.
You can use vnodes if you want to deploy a cluster across multiple regions
(data centres) with one availability zone per region. Each region maintains
a separate ring.
I don't know if you can
Thanks for your answers,
Jonathan, yes it was load avg and iowait was lower than 2% all that time -
the only load was the user one.
Robert, we had -Xmx4012m which was automatically calculated by the default
cassandra-env.sh (1/4 of total memory - 16G) - we didn't change that.
2013/12/5 Robert
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