Idle session and active session throttle

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Enthusiast

Idle session and active session throttle

Hi,

I understand that idle sessions have minimal impac TD and only thing may get impact are locks.so I have 2 questions

-> we have workload throttle limit so no more than 5 users can be active at a time and all beyond that limit will go to delay queue.Now as a recent scenario we had hugh delay queues for this workload.As per TD analyst everything except delay(including idle) will be count as active for that workoad throtte.So we have 5 sessions(3 blocked and 2 idle) and 120 in delayed.As per Analyst

Per TDWM throttle, it will have only 2 states ACTIVE and DELAY.

The sessions which are not in Delay will counted as ACTIVE.

-> Is it best practice to abort idle session.Why and after how long to kill an idle session

3 REPLIES
Teradata Employee

Re: Idle session and active session throttle

Idle or Responding sessions do not count against the throttle limit. Blocked queries count only if they are blocked after they actually start executing (as opposed to being blocked at the "First, we lock..." step before execution starts).

Enthusiast

Re: Idle session and active session throttle

Thanks Fred!!Could you also suggest on idle session,we should abort these.if yes,what is ideal time period after which we should abort such sessions

Teradata Employee

Re: Idle session and active session throttle

I would first watch to see if the number of idle sessions is increasing significantly over time.

 

The main thing is that you don't want to force off sessions just because they are idle at the moment you look. You need to look at the length of time they have been idle since the last request. Also, if you have a middle-tier server that uses a session pool, forcing those sessions off might be a bad idea.

 

If you do decide to abort idle sessions or automate such aborts (e.g. using the Viewpoint Alerts mechanism), I would start out being very conservative - e.g. only consider things that have been idle for multiple days.