Hi,
You don't have to worry about that unless you write with CL = ANY. The sole
method to force hints that I know is to invoke scheduleHintDelivery on
"org.apache.cassandra.db:type=HintedHandoffManager" via JMX but it takes an
endpoint as argument. If you have lots of nodes and several DCs, make sure to
properly set hinted_handoff_throttle_in_kb and max_hints_delivery_threads.
Best,
Romain
Le Samedi 3 septembre 2016 2h59, jerome <[email protected]> a
écrit :
#yiv4261622774 #yiv4261622774 -- P
{margin-top:0;margin-bottom:0;}#yiv4261622774 Hi Matija,
Thanks for your help! The downtime is minimal, usually less than five minutes.
Since it is so short we're not so concerned about the node that's down missing
data, we just want to make sure that before it goes down it replays all the
hints it has so that there won't be any gaps in data on any other nodes for the
hints it has while it's down.
Thanks,Jerome From: Matija Gobec <[email protected]>
Sent: Friday, September 2, 2016 6:05:01 PM
To: [email protected]
Subject: Re: Is it possible to replay hints after running nodetool drain? Hi
Jerome,
The node being drained stops listening to requests but the other nodes being
coordinators for given requests will store hints for that downed node for a
configured period of time (max_hint_window_in_ms is 3 hours by default). If the
downed node is back online in this time window it will receive hints from other
nodes in the cluster and eventually catch up.What is your typical maintenance
downtime?
Regards,Matija
On Fri, Sep 2, 2016 at 10:53 PM, jerome <[email protected]> wrote:
Hello,
As part of routine maintenance for our cluster, my colleagues and I will run a
nodetool drain before stopping a Cassandra node, performing maintenance, and
bringing it back up. We run maintenance as a cron-job with a lock stored in a
different cluster to ensure only node is ever down at a time. We would like to
make sure the node has replayed all its hints before bringing it down to
minimize the potential window in which users might read out-of-date data (we
read at a consistency level of ONE). Is it possible to replay hints after
performing a nodetool drain? The documentation leads me to believe its not
since Cassandra will stop listening for connections from other nodes, but I was
unable to find anything definitive either way. If a node won't replay hints
after a nodetool drain, is there perhaps another way to tell Cassandra to stop
listening for client connections but continue to replay hints to other nodes.
Thanks,Jerome
