Commit Graph

9 Commits (df3996cae3a0fd50eafcebcd567402c6f1c0f9ae)

Author SHA1 Message Date
Mihai Parparita 97b6d3e917 sockstats: remove per-interface stats from Get
They're not needed for the sockstats logger, and they're somewhat
expensive to return (since they involve the creation of a map per
label). We now have a separate GetInterfaces() method that returns
them instead (which we can still use in the PeerAPI debug endpoint).

If changing sockstatlog to sample at 10,000 Hz (instead of the default
of 10Hz), the CPU usage would go up to 59% on a iPhone XS. Removing the
per-interface stats drops it to 20% (a no-op implementation of Get that
returns a fixed value is 16%).

Updates tailscale/corp#9230
Updates #3363

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2 years ago
Will Norris a1d9f65354 ipn,log: add logger for sockstat deltas
Signed-off-by: Will Norris <will@tailscale.com>
Co-authored-by: Melanie Warrick <warrick@tailscale.com>
2 years ago
Mihai Parparita b64d78d58f sockstats: refactor validation to be opt-in
Followup to #7499 to make validation a separate function (
GetWithValidation vs. Get). This way callers that don't need it don't
pay the cost of a syscall per active TCP socket.

Also clears the conn on close, so that we don't double-count the stats.

Also more consistently uses Go doc comments for the exported API of the
sockstats package.

Updates tailscale/corp#9230
Updates #3363

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2 years ago
Mihai Parparita ea81bffdeb sockstats: export as client metrics
Though not fine-grained enough to be useful for detailed analysis, we
might as well export that we gather as client metrics too, since we have
an upload/analysis pipeline for them.

clientmetric.Metric.Add is an atomic add, so it's pretty cheap to also
do per-packet.

Updates tailscale/corp#9230
Updates #3363

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2 years ago
Mihai Parparita 4c2f67a1d0 net/sockstat: fix per-interface statistics not always being available
withSockStats may be called before setLinkMonitor, in which case we
don't have a populated knownInterfaces map. Since we pre-populate the
per-interface counters at creation time, we would end up with an
empty map. To mitigate this, we do an on-demand request for the list of
interfaces.

This would most often happen with the logtail instrumentation, since we
initialize it very early on.

Updates tailscale/corp#9230

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2 years ago
Mihai Parparita f4f8ed98d9 sockstats: add validation for TCP socket stats
We can use the TCP_CONNECTION_INFO getsockopt() on Darwin to get
OS-collected tx/rx bytes for TCP sockets. Since this API is not available
for UDP sockets (or on Linux/Android), we can't rely on it for actual
stats gathering.

However, we can use it to validate the stats that we collect ourselves
using read/write hooks, so that we can be more confident in them. We
do need additional hooks from the Go standard library (added in
tailscale/go#59) to be able to collect them.

Updates tailscale/corp#9230
Updates #3363

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2 years ago
Mihai Parparita 6ac6ddbb47 sockstats: switch label to enum
Makes it cheaper/simpler to persist values, and encourages reuse of
labels as opposed to generating an arbitrary number.

Updates tailscale/corp#9230
Updates #3363

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2 years ago
Mihai Parparita 3e71e0ef68
net/sockstats: remove explicit dependency on wgengine/monitor
Followup to #7177 to avoid adding extra dependencies to the CLI. We
instead declare an interface for the link monitor.

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2 years ago
Mihai Parparita 9cb332f0e2 sockstats: instrument networking code paths
Uses the hooks added by tailscale/go#45 to instrument the reads and
writes on the major code paths that do network I/O in the client. The
convention is to use "<package>.<type>:<label>" as the annotation for
the responsible code path.

Enabled on iOS, macOS and Android only, since mobile platforms are the
ones we're most interested in, and we are less sensitive to any
throughput degradation due to the per-I/O callback overhead (macOS is
also enabled for ease of testing during development).

For now just exposed as counters on a /v0/sockstats PeerAPI endpoint.

We also keep track of the current interface so that we can break out
the stats by interface.

Updates tailscale/corp#9230
Updates #3363

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2 years ago