Object Spawner Major (page) Faults in the SAS Environment Manager

[rsasb]

Hi Admins, I do see, "Object Spawner Major (page) Faults" Alert in the SAS Environment Manager. Description: Major Faults are page faults requiring disk activity. Possible indication of a memory constraint causing slow performance. How do I fix this alert, increasing Heap size might help. But I would like to know are there any downstream impact by doing that.

[Kurt_Bremser]

Since the spawner (along with the metadata server) is usually started with the ID of the SAS installation user, I'd check the constraints of that userID.

OTOH, you might have developed a memory leak. See how long the spawner has been up, and stop/start it. You might consider to set up a periodic restart (eg every night).

With processes where only a single instance will be started on a given machine, you can be liberal with regards to memory consumption, while processes with many instances (workspace servers) should have settings that make sure all expectable concurrent instances fit into available memory.

[JuanS_OCS]

Hello @rsasb,

normally, that kind of a message is just a reflection of other problems, normally caused by the amount , the frequency or the duration of certain sessions. Or its incapability to close orphaned SAS sessions.

An example: Often, this is caused by long stored process sessions, or amount of spanwed STP sessions, which are meant to have short duration. The solution for those is to extend the pool of STP and improve the code for the Stored Processes, or memory settings.

Another example: if object spawner is incapable of closing orphaned SAS Workspace Server sessions, then it has to handle unuseful SAS sessions.

There are many more. I suggest to investigate the behaviour of your spawned SAS sessions. It is very rare the requirement to extend the memory settings of the SAS Object Spawner, even on really BIG deployments. It is a service very optimised.

[SimonDawson]

A one off major fault where a page of memory is retrieved from disk is quite common. Consider that when the linker loads a library unless you call a function in that library the libraries functions stored on disk are never loaded into memory. If you eventually invoke a rarely used function you'll incur a major page fault because the function needs to be into memory from disk when its execute. 

The alert in SAS Environment Manager is there to detect situations where your system is under memory pressure and demand for pages of memory is seeing lots of pages being paged in and out since the demand for pages exceeds the amount of memory available in the system. 

If you are only seeing a handful of major faults this is not something to be concerned about. If your system begins to have major faults occurring constantly for a service like the SAS Object Spawner then this is something to become concerned with and investigate further. The SAS Object Spawner once its warmed up and has been running a while should very infrequently encounter major page faults so seeing it major fault often once its up is an indication of an issue.