PoolTimeoutException while connecting to Cassandra

Hi All, I have downloaded titan-server-0.4.4 and trying to integrate it with Cassandra as backend datasource. Cassandra is running as external on 4 node machine, now I am trying to start Rexster with the Cassandra as my backend source but it comes up with error while initializing. I have even

Reducing tombstones impact in queue access patterns through rolling shards?

Hi, I just came across this recipe by Netflix, that addresses the impact of tombstones in queue access patterns with a time based rolling shard to allow compaction to happen in one shard while the other is ‘busy’. (At least this is what understand from the intro)

RE: How often are JMX Cassandra metrics reset?

And yet OpsCenter shows graphs with ever-changing metrics that show recent performance. Does OpsCenter not get its stats from JMX? From: Robert Coli [mailto:rc...@eventbrite.com] Sent: Wednesday, August 27, 2014 12:56 PM To: user@cassandra.apache.org Subject: Re: How often are JMX Cassandra

Re: How often are JMX Cassandra metrics reset?

On Thu, Aug 28, 2014 at 9:27 AM, Donald Smith donald.sm...@audiencescience.com wrote: And yet OpsCenter shows graphs with ever-changing metrics that show recent performance. Does OpsCenter not get its stats from JMX? 1) Certain JMX endpoints expose recent metrics, or at least used to. These

Re: How often are JMX Cassandra metrics reset?

Those percentile values should be for the lifetime of the node yes. Depending on what version of OpsCenter you are using it is either using the 'recent' metrics described by Rob, or it is using the FiveMinuteRate from JMX as well as doing some of it's own aggregation depending on the rollup size.

Re: Can't Add AWS Node due to /mnt/cassandra/data directory

Awesome, thanks Ben! On Wed, Aug 27, 2014 at 9:14 PM, Ben Bromhead b...@instaclustr.com wrote: Make sure you have also setup the ephemeral drives as a raid device (use mdadm) and mounted it under /mnt/cassandra otherwise your data dir is the os partition which is usually very small. Ben

Commitlog files are not being deleted

Hi all, Shouldn't all commitlog files be auto deleted after replaying, for example after node restart? Using Cassandra 2.0.8 Thanks, Pavel

Re: Commitlog files are not being deleted

On Thu, Aug 28, 2014 at 3:31 PM, Pavel Kogan pavel.ko...@cortica.com wrote: Shouldn't all commitlog files be auto deleted after replaying, for example after node restart? Using Cassandra 2.0.8 No, they're marked clean and recycled. =Rob

RE: How often are JMX Cassandra metrics reset?

The metrics OneMinuteRate, FIveMinuteRate, FifteenMinuteRate, and MeanRate are NOT lifetime values but they’re all counts of requests, not latency. The latency values (Max, Count, 50thPercentile, Mean, etc) ARE lifetime values, I think, and thus would seem to be kinda useless for me, since

Re: How often are JMX Cassandra metrics reset?

In the version of metrics used theres a uniform reservoir and a exponentially weighted one. This is used to compute the min, max, mean, std dev and quantiles. For the timers it uses by default it uses the exp. decaying one which is weighted for the last 5 minutes.