[SERVER-71882] Add serverStatus metric for the number of entries evicted from the telemetry store Created: 06/Dec/22  Updated: 29/Oct/23  Resolved: 07/Feb/23

Status: Closed
Project: Core Server
Component/s: None
Affects Version/s: None
Fix Version/s: 6.3.0-rc0

Type: New Feature Priority: Major - P3
Reporter: Joshua Lapacik (Inactive) Assignee: Maddie Zechar
Resolution: Fixed Votes: 0
Labels: None
Remaining Estimate: Not Specified
Time Spent: Not Specified
Original Estimate: Not Specified

Issue Links:
Related
is related to SERVER-71883 Add serverStatus metric for the numbe... Closed
Assigned Teams:
Query Optimization
Backwards Compatibility: Fully Compatible
Sprint: QO 2023-02-06, QO 2023-02-20
Participants:

 Description   

Currently, LRUKeyValue (used by each partition in the telemetry store to cache entries) memory budget tracker only considers the memory used by the value in the <key, value> pair saved to LRUKeyValue KVList. The memory budget tracker needs to be updates to track all the memory used by LRUKeyValue: the key, the value, the map that associates keys to their position in KVList. This ticket will account for the memory used by the key and the value. A subsequent ticket address tracking the memory used by KVMap.

 

Without this change, entries are only evicted when the amount of memory allocated to a partition is too small to accommodate even a single entry or when 20k queries are run with small cache size and default partition number (1024)**. Thus, in order to record number of entries evict, we need to evict some. And in order to evict, we need to record the amount of memory being used accurately.

 

 

    • for the purposes of this ticket, a unit test will be written to change the number of partitions in order to create a small cache with few partitions that has a small bar for evicting entries.


 Comments   
Comment by Githook User [ 07/Feb/23 ]

Author:

{'name': 'Maddie Zechar', 'email': 'mez2113@columbia.edu', 'username': 'madelinezec'}

Message: SERVER-71882 Add serverStatus metric for the number of entries evicted from the telemetry store
Branch: master
https://github.com/mongodb/mongo/commit/967a6745ba487edaff558e36fdc572c6ca066fea

Generated at Thu Feb 08 06:20:13 UTC 2024 using Jira 9.7.1#970001-sha1:2222b88b221c4928ef0de3161136cc90c8356a66.