We want to be able to fast forward sstable readers. However, just
implementing fast_forward_to() for combined_reader is not enough as the
sstables we are reading from may need to change.
Following patches are going to introduce a combined sstable reader that
derives from combined_reader. To make that possible we first need to
make combined_reader public.
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
This patch introduces the interface for fast forwarding mutation
readers. The main user of this feature is going to be cache which, while
serving range query, may need to read multiple small ranges from the
sstables to populate itself with the missing entries.
Fast forwarding is an alternative to recreating a reader with different
range. Its main advantage is fact that it avoids dropping data that has
already been read.
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
This patch allows sstable readers to be fast forwarded without making it
necessary to recreate the reader (and dropping all buffers in the
process). It is built on top of index_reader and ability of
data_consume_context to be fast forwarded.
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
index_reader is a helper that implements index lookups. Its goal is to
avoid dropping read buffers if they still may be needed (for example to
get end bound of the range or after fast forwarding the reader).
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
That overload was used only by unit test and violated guarantee that
partition range lives until mutation reader is done.
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
is_compactible() will pass on very small regions. full_compaction() is
only used in tests to force objects to be moved due to compaction, so
we want all reclaimable regions to be compacted.
The move constructor of partition_version was not invoking move
constructor of anchorless_list_base_hook. As a result, when
partition_version objects were moved, e.g. during LSA compaction, they
were unlinked from their lists.
This can make readers return invalid data, because not all versions
will be reachable.
It also casues leaks of the versions which are not directly attached
to memtable entry. This will trigger assertion failure in LSA region
destructor. This assetion triggers with row cache disabled. With cache
enabled (default) all segments are merged into the cache region, which
currently is not destroyed on shutdown, so this problem would go
unnoticed. With cache disabled, memtable region is destroyed after
memtable is flushed and after all readers stop using that memtable.
Fixes#1753.
Message-Id: <1476778472-5711-1-git-send-email-tgrabiec@scylladb.com>
Since we are exiting Scylla process in engine().at_exit() using
::_exit(0), even verify_seastar_io_scheduler() throwing an exception,
scylla always exit with 0.
Systemd misunderstands scylla-server.service was shutdown successfully
because of this, so we need to pass correct exit code to ::_exit() here.
Fixes#1674
Signed-off-by: Takuya ASADA <syuu@scylladb.com>
Message-Id: <1475065607-15486-1-git-send-email-syuu@scylladb.com>
* seastar 207bf3d...ccd8649 (3):
> Merge "Augment semaphore with non-blocking operations" from Glauber
> Merge "More dynamic fstream patches" from Paweł
> Merge "fstream: add dynamic adjustments based on stream history" from Paweł
A 1MB response will require 2000 allocations with the current 512-byte
chunk size. Increase it exponentially to reduce allocation count for
larger responses (still respecting the upper limit).
Message-Id: <1476369152-1245-1-git-send-email-avi@scylladb.com>
Memory accounting code was attaching partition_snapshot to
partition_entry in order to calculate the size of partition_version
object. However, it is only allowed if partition_entry doesn't have
any snapshot attached already. In this case it always has one, created
by the flushing reader.
Change the accounting code to reuse existing partition_snapshot reference.
Fixes#1746
Message-Id: <1476449160-9252-1-git-send-email-tgrabiec@scylladb.com>
LSA tries to allocate zones as large as possible (while still leaving
enough free space for the standard allocator). It uses the amount of
free memory in order to guess how much it can get, but that obviously
doesn't account for fragmentation and the allocation attempt may fail.
This patch changes the LSA code so that it doesn't throw in case zone
couldn't be created but just returns a null pointer which should be
more performant if the LSA memory cannot grow any more.
Fixes#1394.
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
Message-Id: <1476435031-5601-1-git-send-email-pdziepak@scylladb.com>
The expected behaviour in the scylla_setup script is that a question
will be followed by the answer.
For example, after asking if the scylla should be run as a service the
relevant actions will be taken before the following question.
This patch address two such mis-orders:
1. the scylla-housekeeping depends on the scylla-server, but the
setup should first setup the scylla-server service and only then ask
(and install if needed) the scylla-housekeeping.
2. The node_exporter should be placed after the io_setup is done.
Fixes#1739
Signed-off-by: Amnon Heiman <amnon@scylladb.com>
Message-Id: <1476370098-25617-1-git-send-email-amnon@scylladb.com>
Change abstract_replication_strategy::create_replication_strategy() to
throw exceptions::configuration_error if replication strategy class
lookup to make sure the error is converted to the correct CQL response.
Fixes#1755
Message-Id: <1476361262-28723-1-git-send-email-penberg@scylladb.com>
* seastar f937fb0...207bf3d (11):
> Merge "iotune: gracefully exit on predictable exceptions" (Fixes#1623)
> core/semaphore: Add semaphore_units::release()
> Merge "rometheus API with grafana uses labels" from Amnon
> core/thread: Fix stack alloc-dealloc mismatch
> core/thread: Make jmp_buf_link::yield_at use the same time point as thread_scheduling_group
> file: support for XFS on older kernels
> reactor: fix bug when handling EBADF in flush_pending_aio()
> prometheus CPU should start in 0
> Collectd: bytes ordering depends on the type
> tests: Check that backtrace() doesn't corrupt signal mask
> core/thread: Add stack guards to seastar thread stacks
If we have a range query involving a wrapping range (i.e., from thrift),
and mutations from both halves of the result are involved, then
we will return the results in the wrong order (and potentially the wrong
partitions) since we order by token, so the results from the second half
of the wrapping range end up before the first.
Fix by splitting the two queries, and merging the second half with lower
priority compared to the first half.
Note: this will be fixed in a better way once we have the sharding iterator,
as then we can query sequentially.
Fixes#1761.
Message-Id: <1476262693-30162-1-git-send-email-avi@scylladb.com>
"This series address two issues that interfere with running the node_exporter as a service in ubuntu 16.
1. The service file should be packed in the deb file
2. When setting the node_exporter as a service it doesn't need to run with scylla use"
* 'amnon/node_exporter_ubuntu_v2' of github.com:cloudius-systems/seastar-dev:
node-exporter service: No need to run as scylla user
debian package: Include the node_exporter service file
the node-exporter does not need to run as scylla user. It can run
without scylla or without the scylla user being configure.
Signed-off-by: Amnon Heiman <amnon@scylladb.com>
"This patch-set re-implements the describe_splits_ex() verb to more closely
follow Cassandra's implementation, on which some clients rely.
Ref #1139
Ref #693"
* 'describe-splits/v2' of github.com:duarten/scylla:
thrift: Implement describe_splits_ex based on Cassandra
storage_service: Implement get_splits() function
sstables: Add function to get key samples
sstables/key: Add to_partition_key function
size_estimates_recorder: Increase estimate accuracy
sstables: Get estimates for a particular range
sstables/key: Make key::kind public
The script mistakenly split value at "," when cpuset list is separated
by comma. Instead of matching possible patterns of the argument, let's
pass all characters until reach to space delimiter or end of line.
Fixes#1716
Signed-off-by: Takuya ASADA <syuu@scylladb.com>
Message-Id: <1476171037-32373-1-git-send-email-syuu@scylladb.com>
This patch re-implements the describe_splits_ex() verb to more closely
follow Cassandra's implementation, on which some clients rely.
Ref #1139
Ref #693
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
This patch implements the get_splits() function in storage_service,
used to split a particular token range in slices of approximately the
specified size, using the sample keys and estimates of the CF's
sstables.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
This patch implements the get_key_samples() function, on which a
future patch will base an implementation of the describe_splits()
thrift verb closer to Cassandra's.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
This patch adds the estimated_keys_for_range() function, which
estimates the number of keys present between the specified range.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
"The version is taken from the installation rather than the API, a mode command
line indicated that this is part of the setup and uuid is used for the
interaction with the checkversion server."
* 'amnon/check_version_on_startup_v3' of github.com:cloudius-systems/seastar-dev:
scylla_setup: Check and report the scylla version
scylla-housekeeping: check version during setup
There is already queue_length-requests_blocked_memory, but it's a
gauge so does not reflect what happened between the sampling points.
total_operations-requests_blocked_memory will allow to see if there
were any (and how many) requests which were blocked by dirty memory.
Message-Id: <1476098616-12682-1-git-send-email-tgrabiec@scylladb.com>
Presents current heap profile recording.
Works in text mode or dumps to collapsed stacks format from which
flame graph can be generated.
To generate a flamegraph:
(gdb) scylla heapprof --flame
Wrote heapprof.stacks
$ flamegraph.pl --colors mem < heapprof.stacks > heapprof.svg
flamegraph.pl comes from:
https://github.com/brendangregg/FlameGraph.git
Text mode example:
(gdb) scylla heapprof --min 100000000
All (274699676, #10213)
\-- void* memory::cpu_pages::allocate_large_and_trim<memory::cpu_pages::allocate_large_aligned(unsigned int, unsigned int)::{lambda(unsigned int, unsigned int)#1}>(unsigned int, memory::cpu_pages::allocate_large_aligned(unsigned int, unsigned int)::{lambda(unsigned int, unsigned int)#1}) + 169 (268435456, #1)
memory::allocate_large_aligned(unsigned long, unsigned long) + 87
memory::allocate_aligned(unsigned long, unsigned long) + 48
aligned_alloc + 9
logalloc::segment_zone::segment_zone() + 304
logalloc::segment_pool::allocate_segment() + 477
logalloc::segment_pool::segment_pool() + 304
__tls_init.part.801 + 72
logalloc::region_group::release_requests() + 1333
logalloc::region_group::add(logalloc::region_group*) + 514
The branches are formatted like this:
-- <symbol> (<size>, #<count>)
Where <size> is total size of live objects and <count> is total
number of live objects, for all objects allocated from paths going
through this node.
Nodes which share the same <size> and <count> are stacked like this:
-- <symbol_1> (<size>, #<count>)
<symbol_2>
<symbol_3>
Message-Id: <1475583334-19524-1-git-send-email-tgrabiec@scylladb.com>
