Which is mainly generational state (terms) and useful LSNs.
Also add /status basic healthcheck request which is now used in tests to
determine the safekeeper is up; this fixes#726.
ref #115
This adds a fast-path for the common case that the record doesn't
cross a page boundary. We now split off a new Bytes directly from the
original input buffer in that case, instead of copying the record to a
new BytesMut. Shaves about 5% of the page server's CPU time on my
laptop, in the 'test_bulk_insert' test.
* Use logging in python tests
* Use f-strings for logs
* Don't log test output while running
* Use only pytest logging handler
* Add more info about pytest logging
* Rename wal_acceptor binary to safekeeper
* Rename wal_acceptor.pid and wal_acceptor.log to safekeeper.pid and safekeeper.log
* Change some mentions of WAL acceptor to safekeeper
* Dockerfile: alias wal_acceptor to safekeeper temporarily until internal scripts are updated
This change brings the following improvements to our build system:
* Now BUILD_TYPE also affects rust apps.
* From now on, cargo will respect `-jN` passed via `make`. However, note
that `rustc` may spawn multiple threads depending on compile flags.
* Cargo is able to cooperate with make to better schedule parallel jobs,
which leads to better build times (-20s in release mode on my machine).
No need to use BytesMut in these functions. Plain Vec is simpler. And
should be marginally faster too; I saw BytesMut functions previously
in 'perf' profile, consuming around 5% of the overall pageserver CPU
time. That's gone with this patch, although I don't see any discernible
difference in the overall performance test results.
Previously, the WAL receiver we would make a decoded copy of the current
Checkpoint before each WAL record, and compare it with the Checkpoint
after the record has been processed. If it has changed, the checkpoint
relish is updated in the repository. That's somewhat expensive, the
Checkpoint::encode() function is visible in 'perf' profile. Change that
so that we set a flag whenever the Checkpoint struct is modified, so that
we dont need to compare the whole struct anymore.
Previously, typos like `BUILD_TYPE=rlease` would silently
lead to building debug binaries. The current approach is also
more future-proof, since we might add `profile`, `valgrind`
as well as other build types.
- perform checkpoint for each tenant repository.
- wait for the completion of all threads.
Add new option 'immediate' to 'pageserver stop' command to terminate the pageserver immediately.
When a WAL record affects multiple pages, we currently duplicate the
record for each affected page. That's a bit wasteful, but not too bad
for b-tree splits and non-hot heap updates that affect two pages. But
buffering GiST index build WAL-logs the whole relation in 32 page chunks,
with one giant WAL record for each 32-page chunk. Currently we duplicate
that giant record for each of the 32 pages, which is really wasteful.
Github issue https://github.com/zenithdb/zenith/issues/720 tracks the
problem. This commit adds a test case for it to demonstrate it.
Whenever we start processing a request, we now enter a tracing "span"
that includes context information like the tenant and timeline ID, and
the operation we're performing. That context information gets attached
to every log message we create within the span. That way, we don't need
to include basic context information like that in every log message, and
it also becomes easier to filter the logs programmatically.
This removes the eplicit timeline and tenant IDs from most log messages,
as you get that information from the enclosing span now.
Also improve log messages in general, dialing down the level of some
messages that are not very useful, and adding information to others.
We now obey the RUST_LOG env variable, if it's set.
The 'tracing' crate allows for different log formatters, like JSON or
bunyan output. The one we use now is human-readable multi-line format,
which is nice when reading the log directly, but hard for
post-processing. For production, we'll probably want JSON output and
some tools for working with it, but that's left as a TODO. The log
format is easy to change.
* `wal_acceptor`: add HTTP handler, /metrics endpoint only, no authentication
* Two gauges are currently reported: `flush_lsn` and `commit_lsn`
* Add `DEFAULT_PG_LISTEN_PORT` and `DEFAULT_PG_LISTEN_PORT` consts for uniformity
The caller is now responsible for lookin up the predecessor layer,
instead. This makes the code simpler, as you don't need to update the
predecessor reference when a layer is frozen or written to disk.
There was a bug in that, as Konstantin noted on discord:
Assume that freeze doesn't create new inmem layer
(maybe_new_open=None). Then we temporary place in historics frozen
layer. Assume that now new put_wal_record request arrives. There is
no open in-mem layer, so it has to create new one. It is looking for
previous layer for read and set it as new in-mem layer
predecessor. But as far as I understand, prev layer should be our
temporary frozen layer. Which will be then removed from
historics.
That leaves the predecessor field of the new in-memory layer pointing
at the frozen in-memory layer that has been removed from the layer map,
preventing it from being removed from memory.
This makes two subtle changes:
1. When the first new layer is created on a branch for a segment that
existed on the ancestor branch, the start_lsn of the new layer is now
the branch point + 1. We were previously slightly confused on what
the branch point LSN meant. It means that all the WAL up to and
*including* the LSN on the old branch is visible to the new branch.
If we mark the start LSN of the new layer as equal to the branch point,
that's wrong, because if there is a WAL record with that LSN on the
predecessor layer, the new layer would hide it. This bug was hidden
when the layer on the new branch contained a direct reference to the
layer in the old branch, as get_page_reconstruct_data() followed that
reference directly when it didn't find the page version in the new
layer. But now that the caller performs the lookup, it will look up
the new layer that doesn't contain the record, and you get an error.
2. InMemoryLayer now always stores the segment size at the beginning
of the layer's LSN range. Previously, get_seg_size() might have
recursed into the predecessor layer to get the size, but now we
avoid that by always copying over the last size from the previous
layer, when a new layer is created.
The dockerignore and dockerfile have also been excluded from being moved into
docker images, saving docker layer cache busts if only those are changed.
Commit ca9af37478 removed the import_timeline_wal() call from here.
After that, the info!() message is bogus, as we no longer load the WAL
from local disk. Also, the logical size assertion is pointless now.
All the changes are in the vendor/postgres side. However, because we now
generate fewer Full Page Writes, the 'branch_behind' test needs to be
modified so that it still generates enough WAL to consume a few WAL
segments.
