Lots of hinted handoff can give you mutations…
> HintedHandoff 0 0 1798 0
> 0
1798 is somewhat high. This is the HH tasks on this node though, can you see HH
running on other nodes in the cluster? What has been happening on this node ?
HH is throttled to avoid this sort of thing, what version are you on ?
Also looks like the disk IO could not keep up with the flushing….
FlushWriter 0 0 5714 0
499
You need to provide some more info on what was happening to nodes before hand.
And check the logs on all machines for errors etc.
Cheers
-----------------
Aaron Morton
Freelance Cassandra Developer
@aaronmorton
http://www.thelastpickle.com
On 5/10/2011, at 9:52 PM, Yi Yang wrote:
> Well what client are you using? And can you give a hint to your node hardware?
> 從我的 BlackBerry® 無線裝置
>
> From: Philippe <watche...@gmail.com>
> Date: Wed, 5 Oct 2011 10:33:21 +0200
> To: user<user@cassandra.apache.org>
> ReplyTo: user@cassandra.apache.org
> Subject: Why is mutation stage increasing ??
>
> Hello,
> I have my 3-node, RF=3 cluster acting strangely. Can someone shed a light as
> to what is going on ?
> It was stuck for a couple of hours (all clients TimedOut). nodetool tpstats
> showed huge increasing MutationStages (in the hundreds of thousands).
> I restarted one node and it took a while to reply GB of commitlog. I've
> shutdown all clients that write to the cluster and it's just weird
>
> All nodes are still showing huge MutationStages including the new one and
> it's either increasing or stable. The pending count is stuck at 32.
> Compactionstats shows no compaction on 2 nodes and dozens of Scrub
> compactions (all at 100%) on the 3rd one. This is a scrub I did last week
> when I encountered assertion errors.
> Netstats shows no streams being exchanged at any node but each on is
> expecting a few Responses.
>
> Any ideas ?
> Thanks
>
> For example (increased to 567062 while I was writing this email)
> Pool Name Active Pending Completed Blocked All
> time blocked
> ReadStage 0 0 18372664517 0
> 0
> RequestResponseStage 0 0 10731370183 0
> 0
> MutationStage 32 565879 295492216 0
> 0
> ReadRepairStage 0 0 23654 0
> 0
> ReplicateOnWriteStage 0 0 7733659 0
> 0
> GossipStage 0 0 3502922 0
> 0
> AntiEntropyStage 0 0 1631 0
> 0
> MigrationStage 0 0 0 0
> 0
> MemtablePostFlusher 0 0 5716 0
> 0
> StreamStage 0 0 10 0
> 0
> FlushWriter 0 0 5714 0
> 499
> FILEUTILS-DELETE-POOL 0 0 773 0
> 0
> MiscStage 0 0 1266 0
> 0
> FlushSorter 0 0 0 0
> 0
> AntiEntropySessions 0 0 18 0
> 0
> InternalResponseStage 0 0 0 0
> 0
> HintedHandoff 0 0 1798 0
> 0
>
>
> Mode: Normal
> Not sending any streams.
> Not receiving any streams.
> Pool Name Active Pending Completed
> Commands n/a 0 1223769753
> Responses n/a 4 1627481305
>
