The checks for preventing to remove a node are very much reference
table centric. We are soon going to add the same checks for replicated
tables. So, make the checks generic such that:
(a) replicated tables fit naturally
(b) we can the same checks in `citus_disable_node`.
We do not use comments starting with # in spec files because it creates
errors from C preprocessor that expects directives after this character.
Instead use C style comments, i.e:
// single line comment
You can also use multiline comments as well
/*
* multi line comment
*/
We re-define the meaning of active shard placement. It used
to only be defined via shardstate == SHARD_STATE_ACTIVE.
Now, we also add one more check. The worker node that the
placement is on should be active as well.
This is a preparation for supporting citus_disable_node()
for MX with multiple failures at the same time.
With this change, the maintanince daemon only needs to
sync the "node metadata" (e.g., pg_dist_node), not the
shard metadata.
Before this commit, we acquire the metadata locks on the reference
tables while removing/disabling a node on all the MX nodes.
Although it has some marginal benefits, such as a concurrent
modification during remove/disable node blocks, instead of erroring
out, the drawbacks seems worse. Both citus_remove_node and citus_disable_node
are not tolerant to multiple node failures.
With this commit, we relax the locks. The implication is that while
a node is removed/disabled, users might see query errors. On the
other hand, this change becomes removing/disabling nodes more
tolerant to multiple node failures.
When refactoring storage layer in #4907, we deleted the code that allows
overwriting a disk page previously written but not known by metadata.
Readers can see the change that introduced the code allows doing so in
commit a8da9acc63.
The reasoning was that; as of 10.2, we started aligning page
reservations (`AlignReservation`) for subsequent writes right after
allocating pages from disk. That means, even if writer transaction
fails, subsequent writes are guaranteed to allocate a new page and write
to there. For this reason, attempting to write to a page allocated
before is not possible for a columnar table that user created when using
v10.2.x.
However, since the older versions of columnar doesn't do that, following
example scenario can still result in writing to such disk page, even if
user now upgraded to v10.2.x. This is because, when upgrading storage to
2.0 (`ColumnarStorageUpdateIfNeeded`), we calculate `reservedOffset` of
the metapage based on the highest used address known by stripe
metadata (`GetHighestUsedAddressAndId`). However, stripe metadata
doesn't have entries for aborted writes. As a result, highest used
address would be computed by ignoring pages that are allocated but not
used.
- User attempts writing to columnar table on Citus v10.0x/v10.1x.
- Write operation fails for some reason.
- User upgrades Citus to v10.2.x.
- When attempting to write to same columnar table, they hit to "attempt
to write columnar data .." error since write operation done in the
older version of columnar already allocated that page, and now we are
overwriting it.
For this reason, with this commit, we re-do the change done in
a8da9acc63.
And for the reasons given above, it wasn't possible to add a test for
this commit via usual code-paths. For this reason, added a UDF only for
testing purposes so that we can reproduce the exact scenario in our
regression test suite.
During pg upgrades, we have seen that it is not guaranteed that a
columnar table will be created after metadata objects got created.
Prior to changes done in this commit, we had such a dependency
relationship in `pg_depend`:
```
columnar_table ----> columnarAM ----> citus extension
^ ^
| |
columnar.storage_id_seq -------------------- |
|
columnar.stripe -------------------------------
```
Since `pg_upgrade` just knows to follow topological sort of the objects
when creating database dump, above dependency graph doesn't imply that
`columnar_table` should be created before metadata objects such as
`columnar.storage_id_seq` and `columnar.stripe` are created.
For this reason, with this commit we add new records to `pg_depend` to
make columnarAM depending on all rel objects living in `columnar`
schema. That way, `pg_upgrade` will know it needs to create those before
creating `columnarAM`, and similarly, before creating any tables using
`columnarAM`.
Note that in addition to inserting those records via installation script,
we also do the same in `citus_finish_pg_upgrade()`. This is because,
`pg_upgrade` rebuilds catalog tables in the new cluster and that means,
we must insert them in the new cluster too.
- [x] Add some more regression test coverage
- [x] Make sure returning works fine in case of
local execution + remote execution
(task->partiallyLocalOrRemote works as expected, already added tests)
- [x] Implement locking properly (and add isolation tests)
- [x] We do #shardcount round-trips on `SerializeNonCommutativeWrites`.
We made it a single round-trip.
- [x] Acquire locks for subselects on the workers & add isolation tests
- [x] Add a GUC to prevent modification from the workers, hence increase the
coordinator-only throughput
- The performance slightly drops (~%15), unless
`citus.allow_modifications_from_workers_to_replicated_tables`
is set to false
Drop extension might cascade to columnar.options before dropping a
columnar table. In that case, we were getting below error when opening
columnar.options to delete records for the columnar table that we are
about to drop.: "ERROR: could not open relation with OID 0".
I somehow reproduced this bug easily when upgrading pg, that is why
adding added the test to after_pg_upgrade_schedule.
We recently introduced a set of patches to 10.2, and introduced 10.2-4
migration version. This migration version only resides on `release-10.2`
branch, and is missing on our default branch. This creates a problem
because we do not have a valid migration path from 10.2 to latest 11.0.
To remedy this issue, I copied the relevant migration files from
`release-10.2` branch, and renamed some of our migration files on
default branch to make sure we have a linear upgrade path.
Before this commit, we required the user to be owner of the shard/table
in order to call lock_shard_resources.
However, that is too restrictive. We can have users with GRANTS
to the table who are not owners of the tables/shards.
With this commit, we allow such patterns.
This change creates a slightly higher abstraction of the `PartitionedResultDestReceiver` where it decouples the partitioning from writing it to a file. This allows for easier reuse for other `DestReceiver`'s that would like to route different tuples to different `DestReceiver`'s.
Originally there was a lot of state kept in `PartitionedResultDestReceiver` to be able to lazily create `FileDestReceivers` when the first tuple arrived for that target. This convoluted the implementation of the processing of tuples with where they should go.
This refactor changes that where it makes the `PartitionedResultDestReceiver` completely agnostic of what kind of Receivers it is writing to. When constructed you pass it a list of `DestReceiver` compatible pointers with the length of `partitionCount`. Internally the `PartitionedResultDestReceiver` keeps track of which `DestReceiver`'s have been started or not, and start them when they first receive a tuple.
Alternatively, if the instantiating code of the `PartitionedResultDestReceiver` wants, the startup can be turned from lazily to eagerly. When the startup is eager (not lazy) all `rStartup` functions on the list of `DestReceiver`'s are called during the startup of the `PartitionedResultDestReceiver` and marked as such.
A downside of this approach is the following. On highly partitioned destinations we now need to allocate a `FileDestReceiver` for every target, _always_. When the data passed into the `PartitionedResultDestReceiver` is highly skewed to a small set of `FileDestReceiver`'s this will waste some memory. Given the small size of a `FileDestReceiver`, and the fact that actual file handles are only created during the processing of the startup of the `FileDestReceiver` I think this memory waste is not a problem. If this would become a problem we could refactor the source list into some kind of generator object which can generate the `DestReceiver`'s on the fly.
* Refactor some checks in citus local tables
* all existing citus local tables are auto converted after upgrade
* Update warning messages in CreateCitusLocalTable
* Hide notice msg for auto converting local tables
* Hide hint msg
Co-authored-by: Ahmet Gedemenli <afgedemenli@gmail.com>
This PR is fixing 2 separate issues related to the local run of citus upgrade tests.
d3e7c825ab fixes the issue that, with our new testing infrastructure, we moved/renamed some of existing folders. This created a problem for local runs of citus upgrade tests since some paths were sensitive to such changes. This commit tries to make it more generic so that this issue is less likely to happen in the future, while also fixing the current issue.
93de6b60c3 we are fixing an issue that a new environment variable was added for citus upgrade tests, which is defined in the CI. 0cb51f8c37/.circleci/config.yml (L294)
This environment variable wasn't set in our local runs hence it would create problems. Instead of defining this environment variable in the local run, we change the citus_upgrade run command to use an existing env variable, which is now also set in the CI.
We fixed some crashes a while back that would only occur in cases where
the value of a distribution column would have result in a high or a very
low hash value. This adds a regression test for those crashes.
This test starts passing because of PR #4508, to be precise commit:
24e60b44a1
When I undo that commit this newly added test starts failing. This adds
this test to make sure we don't regress on this again.
Clang 13 complains about a suspicious string concatenation. It thinks we
might have missed a comma. This adds parentheses to make it clear that
concatenation is indeed what we meant.
There is a vulnerability in mitmproxy with the version we are using.
It would be hard to exploit anything with regards to the artifacts we ship as its only used in our test suite. Still its good hygiene to _not_ use software with known vulnerabilities.
This PR updates the version of python, mitmproxy and the crypto libraries used.
The latest version of mitmproxy for python 3.6 is not patched, hence the upgrade of python.
For our CI images this cascades into upgrading debian as well :)
For CI we bake these versions in our images so we need to update them as well.
Changes to the CI images: https://github.com/citusdata/the-process/pull/65