Turning journal-datasync off to avoid AMQ broker failures due to storage glitches

Hi,

AMQ broker encounters Critical IO errors when there is a glitch in the storage systems while saving the journal data. The IO Errors force AMQ brokers to shut down.
To avoid broker crashing due to storage glitch we found with the engineering team's help that turning journal-datasync off is an option.

Please find the below details on turning off journal-datasync in the broker xml:

• By default, the <journal-datasync> parameter in broker.xml is set to true. Thus, the AMQ broker writes journal data directly to the disk.
• When we set <journal-datasync> to false, AMQ Broker will delegate the responsibility of writing the messages to the disk to the OS cache.
• This ensures that the data is always written to the disk. The only case where it will not be able to write to the disk is when there is a power failure.
• With this option, the OS tuning needs to be done, because the AMQ broker will now share the OS cache to write the journal data to it.
• With this option, we can ensure better performance and more resilience to the disk-related issues.

Following are the parameters that needs to be set for turning off Journal-datasync parameter in broker xmln
<journal-datasync>false</journal-datasync>
<journal-buffer-timeout>0</journal-buffer-timeout>