Go upgrade:
- Go 1.23 is current => use that for release builds
- Go 1.22 is less than one year old, it's desirable to support it.
- The [`Go Toolchains`](https://go.dev/doc/toolchain) stuff is available
in both of these (would also be in Go 1.21). That is quite nice stuff,
but required some changes to how we versions we use in CircleCI and
the `release-docker` Makefile target.
Protobuf upgrade:
- Go to protobuf GH release website
- Download latest locally
- run `sha256sum`
- replace existing pinned hashes
- `make generate`
Deps upgrade:
- `go get -t -u all`
- repository moves aren't handled well automatically, fix manually
- repeat until no changes
package trace:
- introduce the concept of tasks and spans, tracked as linked list within ctx
- see package-level docs for an overview of the concepts
- **main feature 1**: unique stack of task and span IDs
- makes it easy to follow a series of log entries in concurrent code
- **main feature 2**: ability to produce a chrome://tracing-compatible trace file
- either via an env variable or a `zrepl pprof` subcommand
- this is not a CPU profile, we already have go pprof for that
- but it is very useful to visually inspect where the
replication / snapshotter / pruner spends its time
( fixes#307 )
usage in package daemon/logging:
- goal: every log entry should have a trace field with the ID stack from package trace
- make `logging.GetLogger(ctx, Subsys)` the authoritative `logger.Logger` factory function
- the context carries a linked list of injected fields which
`logging.GetLogger` adds to the logger it returns
- `logging.GetLogger` also uses package `trace` to get the
task-and-span-stack and injects it into the returned logger's fields
