Monday, November 26, 2018

Informatica NFS File Systems


Informatica NFS File Systems


Hello All,

As Informatica administrator, recommend admins to know information on file systems (Shared) on Informatica Servers, most of the jobs read/write on share shared file systems and this will cause Latency in jobs and performance is degraded.

Below are few inputs on NFS from Informatica, please make sure to discuss with your Storage or Linux Admins for any latency issues.

• NFSv2 has several limitations in terms of locking, reliability and in ability to access 64-bit file offsets. Also, industry has mostly migrated to NFSv3 and v4.
• NFSv3 has improved file locking support over v2 but remains a stateless protocol dependent on a separate lock manager – this can cause issues with recovery scenarios. Primary concern is with single point of failure in the NFS server. Based on discussions with Netapp & EMC this is resolved in most NAS appliances by integrating the NFS server support into their proprietary file system. Open concern still exists for standalone NFS server processes. Currently supported with Netapp WAFL NAS and EMC Celerra NAS with some caveats. Please see supported shared file system section.
• NFSv4’s new design seems have resolved lingering issues with NFSv3’s locking and recovery and is the preferred option for NFS-driven solutions.
• Critical - maintaining a write lock on the master pmserver lck file used to arbitrate split brain

This indicates a possible latency issue in using the NFSv4 file system between the time the session creating the dynamic mapping completes and the one using it starts and needs to read it. A solution would be to use the Timer task to insert a delay between the sessions to allow the file system to complete before the second session tried to read the file.

Please refer to below Informatica Link for more updates.