This patch has been extracted from #348, where it became unnecessary
after we had decided that we didn't want to measure anything inside
PostgresBackend.
IMO the change is good enough to make its way into the codebase,
even though it brings nothing "new" to the code.
this patch adds support for tenants. This touches mostly pageserver.
Directory layout on disk is changed to contain new layer of indirection.
Now path to particular repository has the following structure: <pageserver workdir>/tenants/<tenant
id>. Tenant id has the same format as timeline id. Tenant id is included in
pageserver commands when needed. Also new commands are available in
pageserver: tenant_list, tenant_create. This is also reflected CLI.
During init default tenant is created and it's id is saved in CLI config,
so following commands can use it without extra options. Tenant id is also included in
compute postgres configuration, so it can be passed via ServerInfo to
safekeeper and in connection string to pageserver.
For more info see docs/multitenancy.md.
It used to be the case that walkeeper's background thread
failed to recognize the end of stream (EOF) signaled by the
`Ok(None)` result of `FeMessage::read`.
Now postgres_backend communicates with the client, passing queries to the
provided handler; we have two currently, for wal_acceptor and pageserver.
Now BytesMut is again used for writing data to avoid manual message length
calculation.
ref #118
This includes the following commits:
35a1c3d521 Specify right LSN in test_createdb.py
d95e1da742 Fix issue with propagation of CREATE DATABASE to the branch
8465738aa5 [refer #167] Fix handling of pg_filenode.map files in page server
86056abd0e Fix merge conflict: set initial WAL position to second segment because of pg_resetwal
2bf2dd1d88 Add nonrelfile_utils.rs file
20b6279beb Fix restoring non-relational data during compute node startup
06f96f9600 Do not transfer WAL to computation nodes: use pg_resetwal for node startup
As well as some older changes related to storing CLOG and MultiXact data as
"pseudorelation" in the page server.
With this revert, we go back to the situtation that when you create a
new compute node, we ship *all* the WAL from the beginning of time to
the compute node. Obviously we need a better solution, like the code
that this reverts. But per discussion with Konstantin and Stas, this
stuff was still half-baked, and it's better for it to live in a branch
for now, until it's more complete and has gone through some review.
Move ReceiveWalConn into its own file. Shuffle constants around so they
are close to the protocol they're associated with, or move them into
postgres_ffi if they seem to be global constants.
It may be more robust to use the TcpStream::peek function, so do all
protocol peeking before creating the protocol object. This reveals the
next cleanup step: rename Connection, since it's no longer the parent of
SendWalConn. Now we peek at the first bytes and choose which kind of
connection object to create.
Serialize objects directly to the stream. This allows us to remove a
bunch of buffer management code, along with the NewSerializer trait that
was a temporary bridge between the old code and the new.
The pieces are:
base Connection
SendWal
ReplicationHandler
There are lots of other changes here:
- Put the replication reader in a background thread; this gets rid
of some hacks with nonblocking mode.
- Stop manually buffering input data; use BufReader instead.
- Use BytesMut a lot less; use Read/Write traits where possible.
If we try to read a few bytes at a time, we will perform a lot more
syscalls than necessary. Wrap the socket in a BufReader, which will
buffer bytes as needed.
This patch started as an effort to support CLI working against remote
pageserver, but turned into a pretty big refactoring.
* CLI now does not look into repository files directly. New commands
'branch_create' and 'identify_system' were introduced into page_service to
support that.
* Branch management that was scattered between local_env and
zenith/main.rs is moved into pageserver/branches.rs. That code could better fit
in Repository/Timeline impl, but I'll leave that for a different patch.
* All tests-related code from local_env went into integration_tests/src/lib.rs as an
extension to PostgresNode trait.
* Paths-generating functions were concentrated around corresponding config
types (LocalEnv and PageserverConf).
Multiple fds writing to the same file doesn't work. One fd will
overwrite the output of the other fd. We were opening log files three
times (stdout, stderr, and slog).
The symptoms can be seen when the program panics; the final file will
have truncated or lost messages. After this change, all messages are
preserved. If panicking and logging are concurrent (and they definitely
can be), some of the messages may be interleaved in slightly
inconvenient ways.
File::try_clone() is essentially `dup` underneath, meaning the two will
share the same file offset.
Add fixes suggested in code review.
In a previous commit, I changed the NodeId field order and types to try
to preserve the exact serialization that was happening. Unfortunately,
that serialization was incorrect and the original struct was mostly
correct.
Change uuid to be a [u8; 16] as it was intended to be a byte array; that
will clearly indicate to serde serializers that no endian swaps will
ever be needed.
Replace XLogRecPtr with Lsn in wal_service.rs .
This removes the last use of XLogSegmentOffset and XLByteToSeg, so
delete them. (replaced by Lsn::segment_offset and Lsn::segment_number.)
