feat: Only keep HTTP headers we want to keep #254
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lizthegrey
reviewed
Sep 29, 2023
| @@ -123,3 +127,23 @@ func (reader *tcpReader) processEvent(requestId int64, entry *entry) { | |||
| DstIp: reader.dstIp, | |||
| } | |||
| } | |||
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| var headersToExtract = []string{ | |||
| "User-Agent", | |||
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that's really the only header you use right now?
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Yes, for now. We were conscious to not over subscribe to too many as headers can be very sensitive.
lizthegrey
approved these changes
Sep 30, 2023
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Which problem is this PR solving?
When processing HTTP request/response pairs, the header structs contain a lot of information we do not care about. From profiling data, we can see a large portion of the agent's live bytes are coming from
textproto.readMimeHeader(), where headers are created. These bytes are held until the request/response pair is processed.This PR adds extracts a copy of the header entries we care about and replaces the Header struct on the request/response, meaning the previous larger Header struct can be GC'd earlier and not wait for pairing to complete.
Short description of the changes
How to verify that this has the expected result
The header that's part of the HTTP request / response now only contains entries we care about and allows the expensive original Header to be cleaned up earlier.