cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Arijit (JIRA)" <j...@apache.org>
Subject [jira] [Comment Edited] (CASSANDRA-13308) Hint files not being deleted on nodetool decommission
Date Thu, 09 Mar 2017 02:35:37 GMT

    [ https://issues.apache.org/jira/browse/CASSANDRA-13308?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15902369#comment-15902369
] 

Arijit edited comment on CASSANDRA-13308 at 3/9/17 2:34 AM:
------------------------------------------------------------

Thanks for looking into this!

The cluster is 10 nodes in size, with about 2 GB of metadata on each node right now. Although
surprisingly, when this happened yesterday,
I saw that nodes on average had 500 MB of hints for the decommissioned node with one node
storing 3 GB of hints.

I don't think there were any range movements happening. I would guess that this is not CASSANDRA-12281,
since I don't see the stack trace for that bug in my jstack output.

I've attached the jstack output (relevant threads from what I could figure out are 28548 and
5832) and a snippet of the log messages during this time.

I didn't think to look at `nodetool netstats`, but it looked like hinted handoff was happening,
albeit slowly (a 100 MB file was getting replayed every 30 minutes according to logs, even
though the node was decommissioned). The streaming for decommission must have completed, from
the fact that logs on the node said it was DECOMMISSIONED?


was (Author: arijit91):
Thanks for looking into this!

The cluster is 10 nodes in size, with about 2 GB of metadata on each node right now. Although
surprisingly, when this happened yesterday,
I saw that nodes on average had 500 GB of hints for the decommissioned node with one node
storing 3 GB of hints.

I don't think there were any range movements happening. I would guess that this is not CASSANDRA-12281,
since I don't see the stack trace for that bug in my jstack output.

I've attached the jstack output (relevant threads from what I could figure out are 28548 and
5832) and a snippet of the log messages during this time.

I didn't think to look at `nodetool netstats`, but it looked like hinted handoff was happening,
albeit slowly (a 100 MB file was getting replayed every 30 minutes according to logs, even
though the node was decommissioned). The streaming for decommission must have completed, from
the fact that logs on the node said it was DECOMMISSIONED?

> Hint files not being deleted on nodetool decommission
> -----------------------------------------------------
>
>                 Key: CASSANDRA-13308
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-13308
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Streaming and Messaging
>         Environment: Using Cassandra version 3.0.9
>            Reporter: Arijit
>         Attachments: 28207.stack, logs
>
>
> How to reproduce the issue I'm seeing:
> Shut down Cassandra on one node of the cluster and wait until we accumulate a ton of
hints. Start Cassandra on the node and immediately run "nodetool decommission" on it.
> The node streams its replicas and marks itself as DECOMMISSIONED, but other nodes do
not seem to see this message. "nodetool status" shows the decommissioned node in state "UL"
on all other nodes (it is also present in system.peers), and Cassandra logs show that gossip
tasks on nodes are not proceeding (number of pending tasks keeps increasing). Jstack suggests
that a gossip task is blocked on hints dispatch (I can provide traces if this is not obvious).
Because the cluster is large and there are a lot of hints, this is taking a while. 
> On inspecting "/var/lib/cassandra/hints" on the nodes, I see a bunch of hint files for
the decommissioned node. Documentation seems to suggest that these hints should be deleted
during "nodetool decommission", but it does not seem to be the case here. This is the bug
being reported.
> To recover from this scenario, if I manually delete hint files on the nodes, the hints
dispatcher threads throw a bunch of exceptions and the decommissioned node is now in state
"DL" (perhaps it missed some gossip messages?). The node is still in my "system.peers" table
> Restarting Cassandra on all nodes after this step does not fix the issue (the node remains
in the peers table). In fact, after this point the decommissioned node is in state "DN"



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)

Mime
View raw message