Re: 【Solr 8.11.2】RejectedExecutionException: Max requests queued per destination 3000 exceeded

[Shawn Heisey]

On 11/9/22 01:10, slly wrote:
   Caused by: java.util.concurrent.RejectedExecutionException: Max requests 
queued per destination 3000 exceeded for 
HttpDestination[http://localhost:8983]@d368dfe,queue=3000,pool=MultiplexConnectionPool@3f16228[c=0/4/4,a=0,i=0,q=3000]
         at 
org.eclipse.jetty.client.HttpDestination.send(HttpDestination.java:293)
         at 
org.eclipse.jetty.client.HttpDestination.send(HttpDestination.java:263)
         at org.eclipse.jetty.client.HttpClient.send(HttpClient.java:600)
         at org.eclipse.jetty.client.HttpRequest.sendAsync(HttpRequest.java:778)
         at org.eclipse.jetty.client.HttpRequest.send(HttpRequest.java:765)
         at 
org.apache.solr.client.solrj.impl.Http2SolrClient.request(Http2SolrClient.java:409)

What's the context of that error?  Are you seeing it on the client side 
using SolrJ with Http2SolrClient?  Does the error also show up in solr.log?

If I'm not mistaken, it's saying that there are more than 3000 requests 
queued up.

Here's another mailing list thread where this was happening.  The 
solution in this case was to switch the client to use http 1.1:

https://www.mail-archive.com/users@solr.apache.org/msg03272.html

The exception they were getting looks almost identical to yours, only 
some of the source code line numbers are different, which is easily 
explained by them being on 8.11.1 and you on 8.11.2.

I wonder whether 8.11 has a bug in http2 and whether it might be fixed 
in 9.x.

Are you actually queuing up thousands of requests faster than Solr can 
process them?

Thanks,
Shawn