This repository has been archived by the owner on Apr 6, 2023. It is now read-only.
feat: instrument cache hit and misses #208
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Dexterp37
commented
Nov 9, 2021
mythmon
suggested changes
Nov 9, 2021
this additionally adds a metric to track the number of items in the in-memory cache.
Dexterp37
force-pushed
the
consvc-1354
branch
from
ea14662
to
913132d
Compare
mythmon
previously requested changes
Nov 9, 2021
merino-cache/src/memory.rs
Outdated
| @@ -174,6 +176,13 @@ impl Suggester { | |||
| ?removed_storage, | |||
| "finished removing expired entries from cache" | |||
| ); | |||
|
|
|||
| metrics_client | |||
| .count("cache.memory.storage_len", items.len_storage() as i64) | |||
There was a problem hiding this comment.
I missed this the first time, but this needs to be metrics_client.gauge, not .count. That's because count is equivalent to incr, but with a larger step. (more specifically, incr is count with n = 1). With count we'd end up with a graph of the integral of the cache size overtime, which definitely isn't what we want.
pjenvey
suggested changes
Nov 9, 2021
merino-cache/src/memory.rs
Outdated
| .take(2) | ||
| .map(|x| String::from_utf8(x).unwrap()) | ||
| .collect(); | ||
| assert!(collected_data.contains(&"merino-test.cache.memory.storage_len:1|c".to_string())); |
There was a problem hiding this comment.
needs updating per the gauge type
docs/data.md
Outdated
Comment on lines
120
to
124
| - `cache.memory.pointers-len` - A counter representing the number of entries in | ||
| the first level of hashing in the in-memory deduped hashmap. | ||
|
|
||
| - `cache.memory.storage-len` - A counter representing the number of entries in | ||
| the second level of hashing in the in-memory deduped hashmap. |
There was a problem hiding this comment.
Suggested change
| - `cache.memory.pointers-len` - A counter representing the number of entries in | |
| the first level of hashing in the in-memory deduped hashmap. | |
| - `cache.memory.storage-len` - A counter representing the number of entries in | |
| the second level of hashing in the in-memory deduped hashmap. | |
| - `cache.memory.pointers-len` - A gauge representing the number of entries in | |
| the first level of hashing in the in-memory deduped hashmap. | |
| - `cache.memory.storage-len` - A gauge representing the number of entries in | |
| the second level of hashing in the in-memory deduped hashmap. |
pjenvey
approved these changes
Nov 9, 2021
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Note: this is based on #205 and will need to be rebased after that gets merged.
This additionally adds a metric to track the number of items in the in-memory cache. Note that this does not add the same count of items for the Redis cache, as it's slightly more involved there and I'd take it as a separate, specific PR.
This contributes toward #207 , but follow-up work is required to fix it.