[LU-14517] Decrease default lru_max_age value

• Type: Improvement
• Resolution: Unresolved
• Priority: Minor
• Assignee: WC Triage
• Reporter: Aurelien Degremont (Inactive)

Description

lru_max_age is set to 65min for ages. This is a looong time and that makes clients keep lots of LDLM locks in cache, and more data in cache. The only reason for that, that I'm aware of, is to help login nodes to avoid them requesting the same locks too often.

I know a lot of sites tune this value to something much smaller. Compute nodes have a more agressive value usually, and the LRU cache is clear between jobs anyway.

I think it would be valuable to change the default value to a much reasonable one to avoid most of users to decrease this value. I think going down to 5 min would be a good move.

If login nodes has to re-enqueue some locks every 5 min I think it is not a problem at all.

 

What do you think of that?

Issue Links

• is duplicated by: LU-17428 reduce default value for lru_max_age to 300s
• is related to: LU-7266 Fix LDLM pool to make LRUR working properly
• is related to: LU-6402 reduce the value of LDLM_POOL_MAX_AGE
• is related to: LU-6529 Server side lock limits to avoid unnecessary memory exhaustion
• is related to: LU-11509 LDLM: replace lock LRU with improved cache algorithm