3.6.3 has been released for linux only. We in supporting clusters
found a case where thread exhaustion can cause election cycles for
time measured in minutes (root cause information to follow). While
unlikely to occur we highly recommend people to upgrade to this
Root cause information:
The root cause of this issue was a blocking operation inside of an
async operation in the threadpool. Although the case we discovered was
an unbounded synchronous connect operation we also identified at least
three other places this could possibly happen including DNS lookups.
As of version 3.6.3 we no longer use mono's code around sending http requests.
Again, you likely want to upgrade to 3.6.3 if running in a linux environment.