Commit aab6b0ee27 introduced the
controversial new IMR format, which relied on a very template-heavy
infrastructure to generate serialization and deserialization code via
template meta-programming. The promise was that this new format, beyond
solving the problems the previous open-coded representation had (working
on linearized buffers), will speed up migrating other components to this
IMR format, as the IMR infrastructure reduces code bloat, makes the code
more readable via declarative type descriptions as well as safer.
However, the results were almost the opposite. The template
meta-programming used by the IMR infrastructure proved very hard to
understand. Developers don't want to read or modify it. Maintainers
don't want to see it being used anywhere else. In short, nobody wants to
touch it.
This commit does a conceptual revert of
aab6b0ee27. A verbatim revert is not
possible because related code evolved a lot since the merge. Also, going
back to the previous code would mean we regress as we'd revert the move
to fragmented buffers. So this revert is only conceptual, it changes the
underlying infrastructure back to the previous open-coded one, but keeps
the fragmented buffers, as well as the interface of the related
components (to the extent possible).
Fixes: #5578
"
Currently inactive readers are stored in two different places:
* reader concurrency semaphore
* querier cache
With the latter registering its inactive readers with the former. This
is an unnecessarily complex (and possibly surprising) setup that we want
to move away from. This series solves this by moving the responsibility
if storing of inactive reads solely to the reader concurrency semaphore,
including all supported eviction policies. The querier cache is now only
responsible for indexing queriers and maintaining relevant stats.
This makes the ownership of the inactive readers much more clear,
hopefully making Benny's work on introducing close() and abort() a
little bit easier.
Tests: unit(release, debug:v1)
"
* 'unify-inactive-readers/v2' of https://github.com/denesb/scylla:
reader_concurrency_semaphore: store inactive readers directly
querier_cache: store readers in the reader concurrency semaphore directly
querier_cache: retire memory based cache eviction
querier_cache: delegate expiry to the reader_concurrency_semaphore
reader_concurrency_semaphore: introduce ttl for inactive reads
querier_cache: use new eviction notify mechanism to maintain stats
reader_concurrency_semaphore: add eviction notification facility
reader_concurrency_semaphore: extract evict code into method evict()
Use the thread_local seastar::testing::local_random_engine
in all seastar tests so they can be reproduced using
the --random-seed option.
Test: unit(dev)
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Message-Id: <20210112103713.578301-2-bhalevy@scylladb.com>
When built by clang this dev-mode test takes ~30 minutes to
complete. Let's reduce this time by reducing the scale of
the test if DEVEL is set.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Require a schema and an operation name to be given to each permit when
created. The schema is of the table the read is executed against, and
the operation name, which is some name identifying the operation the
permit is part of. Ideally this should be different for each site the
permit is created at, to be able to discern not only different kind of
reads, but different code paths the read took.
As not all read can be associated with one schema, the schema is allowed
to be null.
The name will be used for debugging purposes, both for coredump
debugging and runtime logging of permit-related diagnostics.
Previous patches removed those `BOOST_REQUIRE*` macros that could be
invoked from shards other than 0. The reason is that said macros are not
thread-safe, so calling them from multiple shards produces mangled
output to stdout as well as the XML report file. It was assumed that
only these invocations -- from a non-0 shard -- are problematic, but it
turns out even these can race with seastar log messages emitted from
other shards. This patch removes all such macros, replacing them with
the thread safe `require*` functions from `test/lib/test_utils.hh`.
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20200907125309.1199104-1-bdenes@scylladb.com>
Currently, we cannot select more than 2^32 rows from a table because we are limited by types of
variables containing the numbers of rows. This patch changes these types and sets new limits.
The new limits take effect while selecting all rows from a table - custom limits of rows in a result
stay the same (2^32-1).
In classes which are being serialized and used in messaging, in order to be able to process queries
originating from older nodes, the top 32 bits of new integers are optional and stay at the end
of the class - if they're absent we assume they equal 0.
The backward compatibility was tested by querying an older node for a paged selection, using the
received paging_state with the same select statement on an upgraded node, and comparing the returned
rows with the result generated for the same query by the older node, additionally checking if the
paging_state returned by the upgraded node contained new fields with correct values. Also verified
if the older node simply ignores the top 32 bits of the remaining rows number when handling a query
with a paging_state originating from an upgraded node by generating and sending such a query to
an older node and checking the paging_state in the reply(using python driver).
Fixes#5101.
Some tests use the lower level methods directly and meant to use paging
but didn't and nobody noticed. This was revealed by the enforcement of
max result size (introduced in a later patch), which caused these tests
to fail due to exceeding the max result size.
This patch fixes this by setting the `allow_short_reads` slice option.
It is important that all replicas participating in a read use the same
memory limits to avoid artificial differences due to different amount of
results. The coordinator now passes down its own memory limit for reads,
in the form of max_result_size (or max_size). For unpaged or reverse
queries this has to be used now instead of the locally set
max_memory_unlimited_query configuration item.
To avoid the replicas accidentally using the local limit contained in
the `query_class_config` returned from
`database::make_query_class_config()`, we refactor the latter into
`database::get_reader_concurrency_semaphore()`. Most of its callers were
only interested in the semaphore only anyway and those that were
interested in the limit as well should get it from the coordinator
instead, so this refactoring is a win-win.
Use the recently added `max_result_size` field of `query::read_command`
to pass the max result size around, including passing it to remote
nodes. This means that the max result size will be sent along each read,
instead of once per connection.
As we want to select the appropriate `max_result_size` based on the type
of the query as well as based on the query class (user or internal) the
previous method won't do anymore. If the remote doesn't fill this
field, the old per-connection value is used.
This field will replace max size which is currently passed once per
established rpc connection via the CLIENT_ID verb and stored as an
auxiliary value on the client_info. For now it is unused, but we update
all sites creating a read command to pass the correct value to it. In the
next patch we will phase out the old max size and use this field to pass
max size on each verb instead.
The convenience constructor of read_command now has two integer
parameter next to each other. In the next patch we intend to add another
one. This is recipe for disaster, so to avoid mistakes this patch
converts these parameters to tagged integers. This makes sure callers
pass what they meant to pass. As a matter of fact, while fixing up
call-sites, I already found several ones passing `query::max_partitions`
to the `row_limit` parameter. No harm done yet, as
`query::max_partitions` == `query::max_rows` but this shows just how
easy it is to mix up parameters with the same type.
Boost test macros are not thread safe, using them from multiple threads
results in garbled XML test report output.
3f1823a4f0 replaced most of the
thread-unsafe boost test macros in multishard_mutation_query_test, but
one still managed to slip through the cracks. This patch removes that as
well.
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20200529130706.149603-3-bdenes@scylladb.com>
And use it to obtain any query-class specific configuration that was
obtained from `table::config` before, such as the read concurrency
semaphore and the max memory limit for unlimited queries. As all users
of these items get these from the query class config now, we can remove
them from `table::config`.
And use the reader_permit for this instead. This refactoring has
revealed a pre-existing bug in the `test_lifecycle_policy`, which is
also addressed in this patch. The bug is that said policy executes
reader destructions in the background, and these are not waited for. For
some reason, the semaphore -> permit transition pushes these races over
the edge and we start seeing some of these destruction fibers still
being unfinished when test scopes are exited, causing all sorts of
trouble. The solution is to introduce a special gate that tests can use
to wait for all background work to finish, before the test scope is
exited.
Boost test macros are not safe to use in multiple shards (threads).
Doing so will result in their output being interwoven, making it
unreadable and generating invalid XML test reports. There was a lot of
back-and-forth on how to solve this, including introducing thread-safe
wrappers of the boost test macros, that use locks. This patch does
something much simple: it defines a bunch of replacement utility
functions for the used macros. These functions use the thread safe
seastar logger to log messages and throw exceptions when the
test has to be failed, which is pretty much what boost test does too.
With this the previously seen complaint about invalid XML is gone.
Example log messages from the utility functions:
DEBUG 2020-05-27 13:32:54,248 [shard 1] testlog - check_equal(): OK @ validate_result() test/boost/multishard_mutation_query_test.cc:863: ckp{0004fe57c8d2} == ckp{0004fe57c8d2}
DEBUG 2020-05-27 13:32:54,248 [shard 1] testlog - require(): OK @ validate_result() test/boost/multishard_mutation_query_test.cc:855
Fixes: #4774
Tests: unit(dev)
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20200527104426.176342-1-bdenes@scylladb.com>
The constructor of `read_command` is used both by IDL and clients in the
code. However, this constructor has a parameter that is not used by IDL:
`read_timestamp`. This requires that this parameter is the very last in
the list and that new parameters that are used by IDL are added before
it. One such new parameter was `bool is_first_page`. Adding this
parameter right before the read timestamp one created a situation where
the last parameter (read_timestamp) implicitly converts to the one
before it (is_first_page). This means that some call sites passing
`read_timestamp` were now silently converting this to `is_first_page`,
effectively dropping the timestamp.
This patch aims to rectify this, while also avoiding similar accidents
in the future, by making `is_first_page` a `bool_class` which doesn't
have any implicit convertions defined. This change does not break the
ABI as `bool_class` is also sent as a `bool` on the wire.
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Tests: unit(dev)
Message-Id: <20200422073657.87241-1-bdenes@scylladb.com>
We use boost test logging primarily to generate nice XML xunit
files used in Jenkins. These XML files can be bloated
with messages from BOOST_TEST_MESSAGE(), hundreds of megabytes
of build archives, on every build.
Let's use seastar logger for test logging instead, reserving
the use of boost log facilities for boost test markup information.
1. Move tests to test (using singular seems to be a convention
in the rest of the code base)
2. Move boost tests to test/boost, other
(non-boost) unit tests to test/unit, tests which are
expected to be run manually to test/manual.
Update configure.py and test.py with new paths to tests.
