[SERVER-39616] Fix size of data structure for storing optimes/lock acquisitions/number of operations Created: 15/Feb/19 Updated: 29/Oct/23 Resolved: 26/Apr/19 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | None |
| Affects Version/s: | None |
| Fix Version/s: | 4.1.11 |
| Type: | Task | Priority: | Major - P3 |
| Reporter: | Maria van Keulen | Assignee: | Daniel Gottlieb (Inactive) |
| Resolution: | Fixed | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Issue Links: |
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| Backwards Compatibility: | Fully Compatible | ||||||||||||||||
| Sprint: | Storage NYC 2019-03-25, Storage NYC 2019-04-08, Storage NYC 2019-04-22, Storage NYC 2019-05-06 | ||||||||||||||||
| Participants: | |||||||||||||||||
| Description |
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The ticket admission flow control POC makes use of a data structure that stores samples of the total number of operations applied since startup and the total number of IX lock acquisitions since start up at a point in time corresponding to a specific timestamp. It is risky to keep around an in-memory structure that grows in size proportionally to replication lag. This structure should be modified to be of fixed size. For now, the initial fixed size will be ~50 megabytes worth of data, but this size is subject to change and will perhaps be parametrized. Since the oldest entries (entries at the the majority point) are the most valuable information in the structure, it's preferable for the newest samples to lose resolution when the data structure hits its memory limits. Refactor the existing structure to use a deque. This approximation does pose the risk of lag not being able to be adequately throttled in certain scenarios. |
| Comments |
| Comment by Githook User [ 26/Apr/19 ] |
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Author: {'email': 'daniel.gottlieb@mongodb.com', 'name': 'Daniel Gottlieb', 'username': 'dgottlieb'}Message: |
| Comment by Maria van Keulen [ 16/Apr/19 ] |
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This ticket should also make the chosen size of the samples data structure and the sampling frequency user-configurable. |
| Comment by Maria van Keulen [ 09/Apr/19 ] |
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This ticket should also address the TODO comment to make Flow Control runtime configurable. Admin privileges should be required to toggle the value of the parameter. |