feat: cache last scrape results #71
Open
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
eli-jordan
force-pushed
the
feature/cache-stackdriver-scrape-results
branch
from
dea3b3b to
cb9576c
Compare
|
This is an interesting idea. I'm thinking about implementing better options to reduce scrape time. For example, taking a metric filter as URL param. This would allow you to fetch subsets of metrics while not having to run multiple copies of the exporter. Would this help reduce your scrape times? |
|
We've implemented selective scrape params. So this should be less necessary. This change also needs a rebase. |
|
Maybe @fbs is interested in this. |
|
yes, ill give this a go :). |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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.
When having the exporter look at a metric over a large interval, it can take quite some time to fetch all the metrics from StackDriver, due to the large number of data points that need to be fetched. In our particular use case, the fetching takes 3-4mins. With such a long fetch time, its practically not possible to have prometheus not either timeout when scraping or have many time series go stale resulting in instant queries returning no results.
To address this, this PR adds a cache that hold the result of the most recent collection from StackDriver, and this is used to server the metrics endpoint. A new collection will be scheduled and cached once the active one completes.