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tailscale/logtail
Joe Tsai 7a77a2edf1
logtail: optimize JSON processing (#11671)
Changes made:

* Avoid "encoding/json" for JSON processing, and instead use
"github.com/go-json-experiment/json/jsontext".
Use jsontext.Value.IsValid for validation, which is much faster.
Use jsontext.AppendQuote instead of our own JSON escaping.

* In drainPending, use a different maxLen depending on lowMem.
In lowMem mode, it is better to perform multiple uploads
than it is to construct a large body that OOMs the process.

* In drainPending, if an error is encountered draining,
construct an error message in the logtail JSON format
rather than something that is invalid JSON.

* In appendTextOrJSONLocked, use jsontext.Decoder to check
whether the input is a valid JSON object. This is faster than
the previous approach of unmarshaling into map[string]any and
then re-marshaling that data structure.
This is especially beneficial for network flow logging,
which produces relatively large JSON objects.

* In appendTextOrJSONLocked, enforce maxSize on the input.
If too large, then we may end up in a situation where the logs
can never be uploaded because it exceeds the maximum body size
that the Tailscale logs service accepts.

* Use "tailscale.com/util/truncate" to properly truncate a string
on valid UTF-8 boundaries.

* In general, remove unnecessary spaces in JSON output.

Performance:

    name       old time/op    new time/op    delta
    WriteText     776ns ± 2%     596ns ± 1%   -23.24%  (p=0.000 n=10+10)
    WriteJSON     110µs ± 0%       9µs ± 0%   -91.77%  (p=0.000 n=8+8)

    name       old alloc/op   new alloc/op   delta
    WriteText      448B ± 0%        0B       -100.00%  (p=0.000 n=10+10)
    WriteJSON    37.9kB ± 0%     0.0kB ± 0%   -99.87%  (p=0.000 n=10+10)

    name       old allocs/op  new allocs/op  delta
    WriteText      1.00 ± 0%      0.00       -100.00%  (p=0.000 n=10+10)
    WriteJSON     1.08k ± 0%     0.00k ± 0%   -99.91%  (p=0.000 n=10+10)

For text payloads, this is 1.30x faster.
For JSON payloads, this is 12.2x faster.

Updates #cleanup
Updates tailscale/corp#18514

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
7 months ago
..
backoff logtail: use tstime (#8607) 1 year ago
example all: replace logtail.{Public,Private}ID with logid.{Public,Private}ID (#7404) 2 years ago
filch adjust build tags for tamago 1 year ago
.gitignore Move Linux client & common packages into a public repo. 5 years ago
README.md Move Linux client & common packages into a public repo. 5 years ago
api.md all: replace logtail.{Public,Private}ID with logid.{Public,Private}ID (#7404) 2 years ago
buffer.go logtail: require Buffer.Write to not retain the provided slice (#11617) 8 months ago
logtail.go logtail: optimize JSON processing (#11671) 7 months ago
logtail_test.go logtail: optimize JSON processing (#11671) 7 months ago

README.md

Tailscale Logs Service

This github repository contains libraries, documentation, and examples for working with the public API of the tailscale logs service.

For a very quick introduction to the core features, read the API docs and peruse the logs reprocessing example.

For more information, write to info@tailscale.io.