[ https://issues.apache.org/jira/browse/CASSANDRA-5926?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Sylvain Lebresne updated CASSANDRA-5926: ---------------------------------------- Attachment: 5926.txt Attaching patch that switches to MemoryAwareThreadPoolExecutor. One interesting detail is that MATPE always forces corePoolSize == maxPoolSize, so doing that pretty much deprecates the native_transport_min_threads in the yaml. I'd say this is probably fine in practice though. > The native protocol server can deadlock > --------------------------------------- > > Key: CASSANDRA-5926 > URL: https://issues.apache.org/jira/browse/CASSANDRA-5926 > Project: Cassandra > Issue Type: Bug > Reporter: Sylvain Lebresne > Assignee: Sylvain Lebresne > Fix For: 1.2.9 > > Attachments: 5926.txt > > > Until CASSANDRA-5239 (i.e. since StorageProxy is blocking), the native > protocol server needs to use a thread per request being processed. For that, > it currently use a DebuggableThreadPoolExecutor, but with a limited queue. > The rational being that we don't want to OOM if a client overwhelm the > server. Rather, we prefer blocking (which DTPE gives us) on the submission of > new request by the netty worker threads when all threads are busy. > However, as it happens, when netty sends back a response to a query, there is > cases where some events (technically, InterestChanged and WriteComplete > events) are send up the pipeline. And those event are submitted on the > request executor as other requests. Long story short, a request thread can > end blocking on the submission to its own executor, hence deadlocking. > The simplest solution is probably to reuse MemoryAwareThreadPoolExecutor from > netty rather that our own DTPE as it also allow to block task submission when > all threads are busy but knows not to block it's own internal events. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira