[XrdTpc] Only use Curl's low-speed-limit with libcurl v7.38 and later #941
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
Curl's detection of low-speed transfers creates a flood of timeout calls which significantly slows large transfers and increases CPU usage. Fixed in curl/curl@cacdc27f52
Closed
Closed
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Outdated suggestions cannot be applied.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.
Curl's detection of low-speed transfers creates a flood of timeout calls which significantly slows large transfers and increases CPU usage. This is fixed in curl/curl@cacdc27f52 which is unfortunately not present on EL7.
This PR checks the curl version and only enables the low-speed detection when libcurl is new enough to have the fix.
Trying this patch on a production EL7 xrootd server which handles TPC requests, there was a significant drop in xrootd CPU usage: from ~100% busy, down to ~5%.
To see if the system is likely being affected, look for the function
Curl_speedcheckappearing frequently in the gstack output forxrootd.