Socket timeout settings

[Viraj Jasani <vj...@apache.org>]

We have a specific environment where we need to harmonize socket connection
timeouts for all Hadoop daemons and some downstreamers too. While reviewing
the socket connection timeouts set in NetUtils, UrlConnection
(HttpURLConnection), I compiled a list of the following configurations:

   - ipc.client.connect.timeout
   - dfs.client.socket-timeout
   - dfs.datanode.socket.write.timeout
   - dfs.client.fsck.connect.timeout
   - dfs.client.fsck.read.timeout
   - dfs.federation.router.connect.timeout
   - dfs.qjournal.http.open.timeout.ms
   - dfs.qjournal.http.read.timeout.ms
   - dfs.checksum.ec.socket-timeout
   - hadoop.security.kms.client.timeout
   - mapreduce.reduce.shuffle.connect.timeout
   - mapreduce.reduce.shuffle.read.timeout


Moreover, although “dfs.datanode.socket.reuse.keepalive” does not indicate
a direct socket timeout, we set it as SocketOptions#SO_TIMEOUT if
opsProcessed != 0 (to block read on InputStream only for this timeout,
beyond which it would result in SocketTimeoutException). Similarly,
“ipc.ping.interval” and “ipc.client.rpc-timeout.ms” are also used to set
SocketOptions#SO_TIMEOUT on the socket.

It's possible that I may have missed some socket timeout configs in the
above list. If anyone could provide feedback on this list or suggest any
missing configs, it would be greatly appreciated.