Hi,
the write.lock issue I see as well when Solr is not been stopped
gracefully. The write.lock files are then left in the HDFS as they do
not get removed automatically when the client disconnects like a
ephemeral node in ZooKeeper. Unfortunately Solr does also not realize
that it should be owning the lock as it is marked in the state stored in
ZooKeeper as the owner and is also not willing to retry, which is why
you need to restart the whole Solr instance after the cleanup. I added
some logic to my Solr start up script which scans the log files in HDFS
and compares that with the state in ZooKeeper and then delete all lock
files that belong to the node that I'm starting.
regards,
Hendrik
On 21.11.2017 14:07, Joe Obernberger wrote:
Hi All - we have a system with 45 physical boxes running solr 6.6.1
using HDFS as the index. The current index size is about 31TBytes.
With 3x replication that takes up 93TBytes of disk. Our main
collection is split across 100 shards with 3 replicas each. The issue
that we're running into is when restarting the solr6 cluster. The
shards go into recovery and start to utilize nearly all of their
network interfaces. If we start too many of the nodes at once, the
shards will go into a recovery, fail, and retry loop and never come
up. The errors are related to HDFS not responding fast enough and
warnings from the DFSClient. If we stop a node when this is
happening, the script will force a stop (180 second timeout) and upon
restart, we have lock files (write.lock) inside of HDFS.
The process at this point is to start one node, find out the lock
files, wait for it to come up completely (hours), stop it, delete the
write.lock files, and restart. Usually this second restart is faster,
but it still can take 20-60 minutes.
The smaller indexes recover much faster (less than 5 minutes). Should
we have not used so many replicas with HDFS? Is there a better way we
should have built the solr6 cluster?
Thank you for any insight!
-Joe
