Support for deletion of counters is limited in a way that once deleted
they cannot be used again (i.e. tombstone always wins, regardless of the
timestamp). Logic responsible for merging two counter cells already
makes sure that tombstones are handled properly, but it is also
necessary to ensure that higher level tombstones always cover counters.
Live counter cells are collections of shards, each one representing the
sum of all operations performed by a particular replica. This commits
introduces an in-memory representation of counters as well as basic
operations such as merge, difference and hashing.
* seastar c1dbd89...f07f8ed (3):
> Merge "Introduce when_all_succeed()" from Paweł
> tests: adjust collectd test for metric API change
> Merge "DNS query support" from Calle
* seastar 397685c...c1dbd89 (13):
> lowres_clock: drop cache-line alignment for _timer
> net/packet: add missing include
> Merge "Adding histogram and description support" from Amnon
> reactor: Fix the error: cannot bind 'std::unique_ptr' lvalue to 'std::unique_ptr&&'
> Set the option '--server' of tests/tcp_sctp_client to be required
> core/memory: Remove superfluous assignment
> core/memory: Remove dead code
> core/reactor: Use logger instead of cerr
> fix inverted logic in overprovision parameter
> rpc: fix timeout checking condition
> rpc: use lowres_clock instead of high resolution one
> semaphore: make semaphore's clock configurable
> rpc: detect timedout outgoing packets earlier
Includes treewide change to accomodate rpc changing its timeout clock
to lowres_clock.
Includes fixup from Amnon:
collectd api should use the metrics getters
As part of a preperation of the change in the metrics layer, this change
the way the collectd api uses the metrics value to use the getters
instead of calling the member directly.
This will be important when the internal implementation will changed
from union to variant.
Signed-off-by: Amnon Heiman <amnon@scylladb.com>
Message-Id: <1485457657-17634-1-git-send-email-amnon@scylladb.com>
need_preempt() is always true in debug mode. Because of that, this loop
will never be executed. Rewrite it as a do-while loop so we are sure
that it is executed at least once - or exactly once in debug mode.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
Message-Id: <1485913079-1283-1-git-send-email-glauber@scylladb.com>
The per-node limit will be total memory divided by number of shards
instead of just total memory. For example, when Scylla is started with
-c16 -m16G, the commit log will induce flushes on given shard when
unflushed data exceeds on that shard 62MB instead of 1GB.
Fixes#2046.
Message-Id: <1485874534-10939-1-git-send-email-tgrabiec@scylladb.com>
Currently the test does not wait for cache update
to finish before carrying on with the checks.
This makes the test nondeterministic and purely wrong
because checks expect update to be finished.
This patch changes the test to wait for update to finish.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Message-Id: <2a99bba24b1628466d3495332b48ef3ccdb43c26.1485862389.git.piotr@scylladb.com>
An earlier patch of mine was using should_yield to do the same. That
is a better direction, but should_yield() was demonstrably more
expensive so for now we'll go with need_preempt() - since this is
hurting pretty much every latency-dependent workload.
I am also including the scripts that I have used to measure and
compare the various versions of this patch.
The data() method already returns a bytes_opt so there's no need to call to_bytes_opt() again.
Fixes compliation failure on CentOS:
In file included from ./cql3/query_options.hh:51:0,
from ./cql3/cql_statement.hh:47,
from ./cql3/statements/raw/select_statement.hh:45,
from build/release/gen/cql3/CqlParser.hpp:65,
from build/release/gen/cql3/CqlParser.cpp:44:
./cql3/values.hh: In function 'bytes_opt to_bytes_opt(const cql3::raw_value&)':
./cql3/values.hh:184:37: error: no matching function for call to 'to_bytes_opt(bytes_opt)'
return to_bytes_opt(value.data());
Message-Id: <1485761863-28236-1-git-send-email-penberg@scylladb.com>
The reason is the same as why foreground writes are reported instead of
total writes (049ae37d08): It is much easier to see what is going on
this way.
Also fixes a typo in a counter's description.
Fixes#1217
Message-Id: <20170129093412.GS11469@scylladb.com>
This patch series adds support for "unset values" that were introduced
in CQL binary protocol v4. They allow bound statements to skip updates
to some or all of the bound variables.
Unset values are specified using the BoundStatement.unset() method in
the Java driver:
http://docs.datastax.com/en/drivers/java/3.1/com/datastax/driver/core/BoundStatement.html#unset-int-
and using the UNSET_VALUE constant in the Python driver:
https://datastax.github.io/python-driver/api/cassandra/query.html#cassandra.query.UNSET_VALUEFixes#2039.
* 'penberg/cql-unset-values/v2' of github.com:cloudius-systems/seastar-dev:
transport/server: CQL unset value support
cql3/statements/select_statement: Unset value support
cql3/user_types: Unset value support
cql3/tuples: Unset value support
cql3/maps: Unset value support
cql3/sets: Unset value support
cql3/lists: Unset value support
cql3/constants: UNSET_VALUE constant
cql3/constants: Unset value support
cql3/attributes: Unset value support
types.hh: Add field_name_as_string() to user_type_impl type
cql3: Introduce raw_value and raw_value_view types
The quota check is quite old at the moment, and dates back to a time in
which the infrastructure in seastar threads was lacking a lot. It is a
bad check since it will not take into consideration the size of the
partition or the time it takes to merge them.
A better check would at least take need_preempt() into account, so that
we would respect the task quota. That check is now embedded into
should_yield(), so there would no need to check anything else.
Although should_yield() does the job, it is still currently quite
expensive. And because we are in a seastar thread with a computationally
intensive loop, it can hurt latency a lot.
So as a temporary measure, let's at least check for need_preempt() - as
it is hurting real users at the moment - and soon work on making
should_yield() cheaper.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
update is one of our biggest sources of performance issues as far as the
cache is concerned. systemtap can be useful in helping tracking some of
them down.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
