"
The original motivation for the "utils: introduce a loading_shared_values" series was a hinted handoff work where
I needed an on-demand asynchronously loading key-value container (a replica address to a commitlog instance map).
It turned out that we already have the classes that do almost what I needed:
- utils::loading_cache
- sstables::shared_index_lists
Therefore it made sense to find a common ground, unify this functionality and reuse the code both in the classes above and in the
new hinted handoff code.
This series introduces the utils::loading_shared_values that generalizes the sstables::shared_index_lists
API on top of bi::unordered_set with the rehashing logic from the utils::loading_cache triggered by an addition
of an entry to the set (PATCH1).
Then it reworks the sstables::shared_index_lists and utils::loading_cache on top of the new class (PATCH2 and PATCH3).
PATCH4 optimizes the loading_cache for the long timer period use case.
But then we have discovered that we have another "customer" for the loading_cache. Apparently our prepared statements cache
had a birth flaw - it was unlimited in size - unless the corresponding keyspace and/or table are modified/dropped the entries
are never evicted. We clearly need to limit its size and it would also make sense to evict the cache entries that haven't been
used long enough.
This seems like a perfect match for a utils::loading_cache except for prepared statements don't need to be reloaded after
they are created.
Patches starting from PATCH5 are dealing with adding the utils::loading_cache the missing functionality (like making the "reloading"
conditional and adding the synchronous methods like find(key)) and then transitioning the CQL and Thrift prepared statements
caches to utils::loading_cache.
This also fixes #2474."
* 'evict_unused_prepared-v5' of https://github.com/vladzcloudius/scylla:
tests: loading_cache_test: initial commit
cql3::query_processor: implement CQL and Thrift prepared statements caches using cql3::prepared_statements_cache
cql3: prepared statements cache on top of loading_cache
utils::loading_cache: make the size limitation more strict
utils::loading_cache: added static_asserts for checking the callbacks signatures
utils::loading_cache: add a bunch of standard synchronous methods
utils::loading_cache: add the ability to create a cache that would not reload the values
utils::loading_cache: add the ability to work with not-copy-constructable values
utils::loading_cache: add EntrySize template parameter
utils::loading_cache: rework on top of utils::loading_shared_values
sstables::shared_index_list: use utils::loading_shared_values
utils: introduce loading_shared_values
- Transition the prepared statements caches for both CQL and Trhift to the cql3::prepared_statements_cache class.
- Add the corresponding metrics to the query_processor:
- Evictions count.
- Current entries count.
- Current memory footprint.
Fixes#2474
Signed-off-by: Vlad Zolotarov <vladz@scylladb.com>
This fixes a failure in view_schema_test, which starts many instances
of single_node_cql_env. cancel_atomic_deletions() causes later
deletions to fail, which causes some of the test cases to fail.
Message-Id: <1505311250-3118-2-git-send-email-tgrabiec@scylladb.com>
Fixes a hang on shutdown with --smp 2 in perf_fast_forward. The hang
is in sstables::await_background_jobs_on_all_shards(), which is
waiting on sstable deletions. Not all shards agree to delete certain
sstables, because e.g. not all shards decide to compact them
yet. Cancel those deletes after database is stopped on all shards,
like we do in main.cc
Fixes#2796.
Message-Id: <1505292239-26032-1-git-send-email-tgrabiec@scylladb.com>
- introcduced "seastarx.hh" header, which does a "using namespace seastar";
- 'net' namespace conflicts with seastar::net, renamed to 'netw'.
- 'transport' namespace conflicts with seastar::transport, renamed to
cql_transport.
- "logger" global variables now conflict with logger global type, renamed
to xlogger.
- other minor changes
Currently, the code is using bytes_opt and bytes_view_opt to represent
CQL values, which can hold a value or null. In preparation for
supporting a third state, unset value introduced in CQL v4, introduce
new raw_value and raw_value_view types and use them instead.
The new types are based on boost::variant<> and are capable of holding
null, unset values, and blobs that represent a value.
After resharding, sstables may be owned by all shards, which
means that file descriptors and memory usage for metadata will
increase by a factor equal to number of shards. That can easily
lead to OOM.
SSTable components are immutable, so they can be stored in one
shard and shared with others that need it. We use the following
formula to decide which shard will open the sstable and share
it with the others: (generation % smp::count), which is the
inverse of how we calculate generation for new sstables.
So if no resharding is performed, everything is shard-local.
With this approach, resource usage due to loaded sstables will
be evenly distributed among shards.
For this approach to work, we now only populate keyspaces from
shard 0. It's now the sole responsible for iterating through
column family dirs. In addition, most of population functions
are now free and take distributed database object as parameter.
Fixes#1951.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
This reverts commit aa392810ff, reversing
changes made to a24ff47c637e6a5fd158099b8a65f1191fc2d023; it uses
boost::intrusive::detail directly, which it must not, and doesn't compile on
all boost versions as a consequence.
This patch introduces the do_with_cql_env_thread() function, which
behaves like do_with_cql_env() except that it executes the
user-specified function in the context of a Seastar thread.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
If exception is triggered early in boot when doing an I/O operation,
scylla will fail because io checker calls storage service to stop
transport services, and not all of them were initialized yet.
Scylla was failing as follow:
scylla: ./seastar/core/sharded.hh:439: Service& seastar::sharded<Service>::local()
[with Service = gms::gossiper]: Assertion `local_is_initialized()' failed.
Aborting on shard 0.
Backtrace:
0x000000000048a2ca
0x000000000048a3d3
0x00007fc279e739ff
0x00007fc279ad6a27
0x00007fc279ad8629
0x00007fc279acf226
0x00007fc279acf2d1
0x0000000000c145f8
0x000000000110d1bc
0x000000000041bacd
0x00000000005520f1
0x00007fc279aeaf1f
Aborted (core dumped)
Refs #883.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Signed-off-by: Asias He <asias@scylladb.com>
Message-Id: <963f7b0f5a7a8a1405728b414a7d7a6dccd70581.1479172124.git.asias@scylladb.com>
There are places in which we need to use the column family object many
times, with deferring points in between. Because the column family may
have been destroyed in the deferring point, we need to go and find it
again.
If we use lw_shared_ptr, however, we'll be able to at least guarantee
that the object will be alive. Some users will still need to check, if
they want to guarantee that the column family wasn't removed. But others
that only need to make sure we don't access an invalid object will be
able to avoid the cost of re-finding it just fine.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
Message-Id: <722bf49e158da77ff509372c2034e5707706e5bf.1478111467.git.glauber@scylladb.com>
Currently start() is not prepared to handle exceptions thrown from
service initialization. It's easy to trigger such exceprion by
starting two tests at the same time, which will result in socket bind
error.
Exception thrown from start() typically results in assertion failures
like this one:
seastar::sharded<Service>::~sharded() [with Service = database]: Assertion `_instances.empty()' failed.
This patch fixes the problem by combining start() and stop() in a
single do_with() and using RAII for stopping services.
Now exceptions thrown from service initialization should stop services
in proper order and let the original exception to pass
through. Example result:
fatal error in "test_new_schema_with_no_structural_change_is_propagated": std::runtime_error: bind: Address already in use
Message-Id: <1458768018-27662-1-git-send-email-tgrabiec@scylladb.com>
Since calculate_pending_ranges will modify token_metadata, we need to
replicate to other shards. With this patch, when we call
calculate_pending_ranges, token_metadata will be replciated to other
non-zero shards.
In addition, it is not useful as a standalone class. We can merge it
into the storage_service. Kill one singleton class.
Fixes#1033
Refs #962
Message-Id: <fb5b26311cafa4d315eb9e72d823c5ade2ab4bda.1457943074.git.asias@scylladb.com>
Fixes#868.
Registerring exit hooks while reactor is already iterating over exit
hooks is not allowed and currently leads to undefined behavior
observed in #868. While we should make the failure more user friendly,
registering exit hooks concurrently with shutdown will not be allowed.
We don't expect exit hooks to be registered after exit starts because
this would violate the guarantee which says that exit hooks are
executed in reverse order of registration. Starting exit sequence in
the middle of initialization sequence would result in use after free
errors. Btw, I'm not sure if currently there's anything which prevents
this
To solve this problem, move the exit hook to initilization
sequence. In case of tests, the cleanup has to be called explicitly.
Time a node waits after sending gossip shutdown message in milliseconds.
Reduces ./cql_query_test execution time
from
real 2m24.272s
user 0m8.339s
sys 0m10.556s
to
real 1m17.765s
user 0m3.698s
sys 0m11.578
The intent is to make data returned by queries always conform to a
single schema version, which is requested by the client. For CQL
queries, for example, we want to use the same schema which was used to
compile the query. The other node expects to receive data conforming
to the requested schema.
Interface on shard level accepts schema_ptr, across nodes we use
table_schema_version UUID. To transfer schema_ptr across shards, we
use global_schema_ptr.
Because schema is identified with UUID across nodes, requestors must
be prepared for being queried for the definition of the schema. They
must hold a live schema_ptr around the request. This guarantees that
schema_registry will always know about the requested version. This is
not an issue because for queries the requestor needs to hold on to the
schema anyway to be able to interpret the results. But care must be
taken to always use the same schema version for making the request and
parsing the results.
Schema requesting across nodes is currently stubbed (throws runtime
exception).
Current service initialization is a total mess in cql_test_env. Start
the service the same order as in main.cc.
Fixes#715, #716
'./test.py --mode release' passes.
Test was failing because _qp (distributed<cql3::query_processor>) was stopped
before _db (distributed<database>).
Compaction manager is member of database, and when database is stopped,
compaction manager is also stopped. After a2fb0ec9a, compaction updates the
system table compaction history, and that requires a working query context.
We cannot simply move _qp->stop() to after _db->stop() because the former
relies on migration_manager and storage_proxy. So the most obvious fix is to
clean the global variable that stores query context after _qp was stopped.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
With this patch, start two nodes
node 1:
scylla --rpc-address 127.0.0.1 --broadcast-rpc-address 127.0.0.11
node 2:
scylla --rpc-address 127.0.0.2 --broadcast-rpc-address 127.0.0.12
On node 1:
cqlsh> SELECT rpc_address from system.peers;
rpc_address
-------------
127.0.0.12
which means client should use this address to connect node 2 for cql and
thrift protocol.
We use boost::any to convert to and from database values (stored in
serlialized form) and native C++ values. boost::any captures information
about the data type (how to copy/move/delete etc.) and stores it inside
the boost::any instance. We later retrieve the real value using
boost::any_cast.
However, data_value (which has a boost::any member) already has type
information as a data_type instance. By teaching data_type intances about
the corresponding native type, we can elimiante the use of boost::any.
While boost::any is evil and eliminating it improves efficiency somewhat,
the real goal is growing native type support in data_type. We will use that
later to store native types in the cache, enabling O(log n) access to
collections, O(1) access to tuples, and more efficient large blob support.
Since 4641dfff24 "service: Copy client
state to query state" after executing a query client state needs to be
merged back. If that's not done client_state::_last_timestamp_micros
won't be advanced properly and mutations originating from the same
source may have exactly the same timestamp.
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
cql_query_test hasn't configured Broadcast address before
it was used for the first time.
Broadcast address is an essential Node's configuration.
There is an assert in utils::fb_utils::get_broadcast_address()
that ensures that broadcast address has been properly configured
before it's used for the first time and it is triggered without
this patch.
Signed-off-by: Vlad Zolotarov <vladz@cloudius-systems.com>
