Details
Major Description
Hi All,
When we issue commit through curl command, not all the shards are getting `start commit` requests at the same time.
Solr Setup Detail : (Running in solrCloud mode)
It has 6 shards, and each shard has only one replica (which is also a
leader) and the replica type is NRT.
Each shards are hosted on the separate physical host.
Zookeeper => We are using external zookeeper ensemble (3 separate node
cluster)
Shard and Host name
shard1_0=>solr_199
shard1_1=>solr_200
shard2_0=> solr_254
shard2_1=> solr_132
shard3_0=>solr_133
shard3_1=>solr_198
Request rate on the system is currently zero and only hourly indexing
running on it.
We are using curl command to issue commit.
curl
"http://solr_254:8389/solr/my_collection/update?openSearcher=true&commit=true&wt=json"
(Using solr_254 host to issue commit)
On using the above command all the shards have started processing commit (i.e
getting `start commit` request) except the one used in curl command (i.e
shard2_0 which is hosted on solr_254). Individually each shards takes around
10 to 12 min to process hard commit (most of this time is spent on reloading
external files).
As per logs, shard2_0 is getting `start commit` request after 10 minutes
(approx). This leads to following timeout error.
2020-12-06 18:47:47.013 ERROR org.apache.solr.client.solrj.SolrServerException: Timeout occured while waiting response from server at: http://solr_132:9744/solr/my_collection_shard2_1_replica_n21/update?update.distrib=TOLEADER&distrib.from=http%3A%2F%2Fsolr_254%3A9744%2Fsolr%2Fmy_collection_shard2_0_replica_n11%2F at org.apache.solr.client.solrj.impl.Http2SolrClient.request(Http2SolrClient.java:407) at org.apache.solr.client.solrj.impl.Http2SolrClient.request(Http2SolrClient.java:753) at org.apache.solr.client.solrj.impl.ConcurrentUpdateHttp2SolrClient.request(ConcurrentUpdateHttp2SolrClient.java:369) at org.apache.solr.client.solrj.SolrClient.request(SolrClient.java:1290) at org.apache.solr.update.SolrCmdDistributor.doRequest(SolrCmdDistributor.java:344) at org.apache.solr.update.SolrCmdDistributor.lambda$submit$0(SolrCmdDistributor.java:333) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at com.codahale.metrics.InstrumentedExecutorService$InstrumentedRunnable.run(InstrumentedExecutorService.java:180) at org.apache.solr.common.util.ExecutorUtil$MDCAwareThreadPoolExecutor.lambda$execute$0(ExecutorUtil.java:210) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748) Caused by: java.util.concurrent.TimeoutException at org.eclipse.jetty.client.util.InputStreamResponseListener.get(InputStreamResponseListener.java:216) at org.apache.solr.client.solrj.impl.Http2SolrClient.request(Http2SolrClient.java:398) ... 13 more
Above timeout error is between solr_254 and solr_132. Similar errors are
there between solr_254 and other 4 shards
Since query load is zero, mostly CPU utilization is around 3%.
After issuing curl commit command, CPU goes up to 14% on all shards except
shard2_0 (host: solr_254, the one used in curl command).
And after 10 minutes (i.e after getting the `start commit` request) CPU on
shard2_0 also goes up to 14%.
As I mentioned earlier each shards take around 10-12 mins to process commit
and due to delay in starting commit process on one shard (shard2_0) our
overall commit time is doubled now. (22-24 minutes approx).
We are observing this delay in both hard and soft commit.
In our solr-5.4.0(having similar setup), we use the similar curl command to issue commit, and there all the shards are getting `start commit` request at same time. Including the one used in curl command.
Impact After deleting external files:
In order to nullify the impact of external files, I had deleted external
files from all the shards and issued commit through the curl command. Commit
operation got completed in 3 seconds. Individual shards took 1.5 seconds to
complete the commit operation. But there was a delay of around 1.5 seconds
on the shard whose hostname was used to issue the commit. Hence overall
commit time is 3 seconds.
During this operation, there was no timeout or any other kind of error
(except `external file not found` error which is expected).
