Bug #106751 Connect timeout too long towards MGMD nodes
Submitted: 16 Mar 2022 17:25 Modified: 17 Mar 2022 5:37
Reporter: Mikael Ronström Email Updates:
Status: Verified Impact on me:
None 
Category:MySQL Cluster: Cluster (NDB) storage engine Severity:S3 (Non-critical)
Version:8.0.28 OS:Any
Assigned to: CPU Architecture:Any

[16 Mar 2022 17:25] Mikael Ronström
Description:
If a hostname in config.ini for a MGM Server is a existing
IP address, but no computer is using the IP, the connect towards
this IP address will timeout.

In the mgmapi.cpp this timeout is set to the generic timeout
for any MGM API handling which is 60 seconds. However this timeout
is also used by thread that connects to TCP servers. This means that
every time a connect is attempted towards this node the thread will
block for 60 seconds.

Other API nodes use a connect timeout of 3 seconds which is more reasonable.

How to repeat:
Create a config with a correct IP address not used by any computer.
Use this IP for a second MGM Server.

Suggested fix:
Introduce new variable connect_timeout in mgmapi data structure and set this
by default to 3000 milliseconds. Ensure that the MGM API call to set
connect timeout use this variable as well.
[17 Mar 2022 5:37] MySQL Verification Team
Hello Mikael,

Thank you for the report and feedback.

Sincerely,
Umesh