download operations of all timelines for one tenant are now grouped
together so when attach is invoked pageserver downloads all of them
and registers them in a single apply_sync_status_update call so
branches can be used safely with attach/detach
Resolves#1488.
- implemented `GET tenant/:tenant_id/timeline/:timeline_id/wal_receiver` endpoint
- returned `thread_id` in `thread_mgr::spawn`
- added `latest_gc_cutoff_lsn` field to `LocalTimelineInfo` struct
Add tenant config API and 'zenith tenant config' CLI command.
Add 'show' query to pageserver protocol for tenantspecific config parameters
Refactoring: move tenant_config code to a separate module.
Save tenant conf file to tenant's directory, when tenant is created to recover it on pageserver restart.
Ignore error during tenant config loading, while it is not supported by console
Define PiTR interval for GC.
refer #1320
We have these methods for some time in the API, so mentioning them in the
spec could be useful for console (see zenithdb/console#867), as we generate
pageserver HTTP API golang client there.
This is a backwards-incompatible change. The new pageserver cannot
read repositories created with an old pageserver binary, or vice
versa.
Simplify Repository to a value-store
------------------------------------
Move the responsibility of tracking relation metadata, like which
relations exist and what are their sizes, from Repository to a new
module, pgdatadir_mapping.rs. The interface to Repository is now a
simple key-value PUT/GET operations.
It's still not any old key-value store though. A Repository is still
responsible from handling branching, and every GET operation comes
with an LSN.
Mapping from Postgres data directory to keys/values
---------------------------------------------------
All the data is now stored in the key-value store. The
'pgdatadir_mapping.rs' module handles mapping from PostgreSQL objects
like relation pages and SLRUs, to key-value pairs.
The key to the Repository key-value store is a Key struct, which
consists of a few integer fields. It's wide enough to store a full
RelFileNode, fork and block number, and to distinguish those from
metadata keys.
'pgdatadir_mapping.rs' is also responsible for maintaining a
"partitioning" of the keyspace. Partitioning means splitting the
keyspace so that each partition holds a roughly equal number of keys.
The partitioning is used when new image layer files are created, so
that each image layer file is roughly the same size.
The partitioning is also responsible for reclaiming space used by
deleted keys. The Repository implementation doesn't have any explicit
support for deleting keys. Instead, the deleted keys are simply
omitted from the partitioning, and when a new image layer is created,
the omitted keys are not copied over to the new image layer. We might
want to implement tombstone keys in the future, to reclaim space
faster, but this will work for now.
Changes to low-level layer file code
------------------------------------
The concept of a "segment" is gone. Each layer file can now store an
arbitrary range of Keys.
Checkpointing, compaction
-------------------------
The background tasks are somewhat different now. Whenever
checkpoint_distance is reached, the WAL receiver thread "freezes" the
current in-memory layer, and creates a new one. This is a quick
operation and doesn't perform any I/O yet. It then launches a
background "layer flushing thread" to write the frozen layer to disk,
as a new L0 delta layer. This mechanism takes care of durability. It
replaces the checkpointing thread.
Compaction is a new background operation that takes a bunch of L0
delta layers, and reshuffles the data in them. It runs in a separate
compaction thread.
Deployment
----------
This also contains changes to the ansible scripts that enable having
multiple different pageservers running at the same time in the staging
environment. We will use that to keep an old version of the pageserver
running, for clusters created with the old version, at the same time
with a new pageserver with the new binary.
Author: Heikki Linnakangas
Author: Konstantin Knizhnik <knizhnik@zenith.tech>
Author: Andrey Taranik <andrey@zenith.tech>
Reviewed-by: Matthias Van De Meent <matthias@zenith.tech>
Reviewed-by: Bojan Serafimov <bojan@zenith.tech>
Reviewed-by: Konstantin Knizhnik <knizhnik@zenith.tech>
Reviewed-by: Anton Shyrabokau <antons@zenith.tech>
Reviewed-by: Dhammika Pathirana <dham@zenith.tech>
Reviewed-by: Kirill Bulatov <kirill@zenith.tech>
Reviewed-by: Anastasia Lubennikova <anastasia@zenith.tech>
Reviewed-by: Alexey Kondratov <alexey@zenith.tech>
* Add --id argument to safekeeper setting its unique u64 id.
In preparation for storage node messaging. IDs are supposed to be monotonically
assigned by the console. In tests it is issued by ZenithEnv; at the zenith cli
level and fixtures, string name is completely replaced by integer id. Example
TOML configs are adjusted accordingly.
Sequential ids are chosen over Zid mainly because they are compact and easy to
type/remember.
* add node id to pageserver
This adds node id parameter to pageserver configuration. Also I use a
simple builder to construct pageserver config struct to avoid setting
node id to some temporary invalid value. Some of the changes in test
fixtures are needed to split init and start operations for envrionment.
Co-authored-by: Arseny Sher <sher-ars@yandex.ru>
Previous version of spec caused parsing errors in generated clients
as return type is object not array, also one field was missing. In
a passing set `format: hex` on ancestor_id too as value conforms to
that format.
This patch includes attach/detach http endpoints in pageservers. Some
changes in callmemaybe handling inside safekeeper and an integrational
test to check migration with and without load. There are still some
rough edges that will be addressed in follow up patches
Out of scope LSNs include pre initdb LSNs, and LSNs prior to
latest_gc_cutoff.
To get there there was also two cleanups:
* Fix error handling in Execute message handler. This fixes behaviour
when basebackup retured an error. Previously pageserver thread just
died.
* Remove "ancestor" file which previously contained ancestor id and
branch lsn. Currently the same data can be obtained from metadata file.
And just the way we handled ancestor file in the code introduced the
case when branching fails timeline directory is created but there is no data in it
except ancestor file. And this confused gc because it scans
directories. So it is better to just remove ancestor file and clean up
this timeline directory creation so it happens after all validity
checks have passed
This calculation is not that heavy but it is needed only in tests, and
in case the number of tenants/timelines is high the calculation can take
noticeable time.
Resolves https://github.com/zenithdb/zenith/issues/804
