MySQL Bugs: #20418: NdbConnection::connect() and DNS timeouts

Bug #20418	NdbConnection::connect() and DNS timeouts
Submitted:	13 Jun 2006 10:30	Modified:	25 May 2007 17:37
Reporter:	Hartmut Holzgraefe
Status:	Analyzing
Category:	Server: Cluster	Severity:	S3 (Non-critical)
Version:	mysql-5.0	OS:	Sun Solaris (Solaris)
Assigned to:	Gustaf Thorslund	Target Version:
Triage:	Triaged: D4 (Minor) / R6 (Needs Assessment) / E6 (Needs Assessment)

Description:
When trying to connect an API node to the cluster while the management nodes DNS hostname
is not resolveable on the API client side due to DNS problems connect() can get stuck for
several minutes until finaly receiving a DNS lookup timeout error. The connect()
parameters for "number of retries" and "time between retries" implicitly suggest that one
has full control over the timeing behavior of the connect() call and that one can rely on
connect() returning after e.g. max. 15s when specifying 3 retries and 5s delays between
retries.

How to repeat:
see description

Suggested fix:
Use async DNS lookups or move DNS lookups to a seperate application thread and terminate
this after the retry delay time has expired

With mgmapi timeouts (specifically, with connect_timeout and now mgmapi timeouts) I don't
think this should be a problem. If can be repeated with latest 5.1, reopen.

I don't have the intention of backporting mgmapi timeouts to 5.0 though.

No feedback was provided for this bug for over a month, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".

Server bug here in progress, http://bugs.mysql.com/38247