4 Commits (8abe080fd6d04dc5efb074ee0764a9bfd39c82d2)

Author	SHA1	Message	Date
Owen Diehl	acb40ed40e	Eager stream merge (#8968) ... This PR introduces a specialized heap based datastructure to merge incoming log results in the frontend. Recently we've experienced an increase in OOMs on frontends due to logs queries which match lots of data. Sharded requests in loki split based on the amount of data we expect and some queries see thousands of sub requests. For log queries, we'll fetch up the `limit` from each shard, return them to the frontend, and merge. High shard counts * limit log lines, especially combined with large log lines (in byte terms) are accumulated on the frontend. Once they all are received, the frontend merges them. This creates opportunity for OOMs as it can hold up a lot of memory. This PR addresses one of these problems by eagerly accumulating responses as they're received and only retaining a total `limit` number of entries. There's still OOM potential due to race conditions between sub requests returning to the query-frontend and the query-frontend merging other sub requests, but this definitely improves the situation. I've been able to consistently run large limited queries that touch TBs of data (i.e. `{cluster=~".+"} |= "a"`) that previously OOMed frontends. --------- Signed-off-by: Owen Diehl <ow.diehl@gmail.com>	3 years ago
Sandeep Sukhani	89d81020ce	fix lint issues from PR 7804 (#7814) ... **What this PR does / why we need it**: I had enabled auto-merge in PR #7804, but somehow it still merged the PR without all the checks passing. This PR fixes the failing lint and tests.	3 years ago
Travis Patterson	c1bccac141	Results cache fix improvements (#7444) ... Move middleware to someplace more sensible and incorporate feedback missed in the review for this.	3 years ago
Travis Patterson	f2297d3d2a	Fix result cache misses on sharded queries (#7429) ... Headers weren't being propagated from query responses on sharded queries causing result cache misses. This PR: - Adds headers to `logproto.Result` so we can save response headers as they come back from queries - Metric-query results are turned into numbers well away from where responses are sent to the frontend: save all headers in the context so they can be pulled out when the final result is calculated - Propagate headers in the final responses	3 years ago