The multishard reader has to combine the output of all shards into a
single fragment stream. To do that, each time a `partition_start` is
read it has to check if there is another partition, from another shard,
that has to be emitted before this partition. Currently for this it
uses the partitioner. At every partition start fragment it checks if the
token falls into the current shard sub-range. The shard sub-range is the
continuous range of tokens, where each token belongs to the same shard.
If the partition doesn't belong to the current shard sub-range the
multishard reader assumes the following shard sub-range of the next shard
will have data and move over to it. This assumption will however only
stand on very dense tables, and will fail miserably on less dense
tables, resulting in the multishard reader effectively iterating over
the shard sub-ranges (4096 in the worst case), only to find data in just
a few of them. This resulted in high user-perceived latency when
scanning a sparse table.
This patch replaces this algorithm with one based on a shard heap. The
shards are now organized into a min-heap, by the next token they have
data for. When a partition start fragment is read from the current
shard, its token is compared to the smallest token in the shard heap. If
smaller, we continue to read from the current shard. Otherwise we move
to the shard with the smallest token. When constructing the reader, or
after fast-forwarding we don't know what first token each reader will
produce. To avoid reading in a partition from each reader, we assume
each reader will produce the first token from the first shard sub-range
that overlaps with the query range. This algorithm performs much better
on sparse tables, while also being slightly better on dense tables.
I did only a very rough measurement using CQL tracing. I populated a
table with four rows on a 64 shards machine, then scanned the entire
table.
Time to scan the table (microseconds):
before 27'846
after 5'248
Fixes: #4125
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <d559f887b650ab8caa79ad4d45fa2b7adc39462d.1548846019.git.bdenes@scylladb.com>
"
This is a first step in fixing #3988.
"
* 'espindola/large-row-warn-only-v4' of https://github.com/espindola/scylla:
Rename large_partition_handler
Print a warning if a row is too large
Remove defaut parameter value
Rename _threshold_bytes to _partition_threshold_bytes
keys: add schema-aware printing for clustering_key_prefix
Three error messages were supposed to include a column name, but a "{}"
was missing in the format so the given column name didn't actually appear
in the error message. So this patch adds the missing {}'s.
Fixes#4183.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20190203112100.13031-1-nyh@scylladb.com>
Adds new columns to the "Page spans" table named "large [B]" and
"[spans]", which shows how much memory is allocated in spans of given
size. Excludes spans used by small pools.
Useful in determining what is the size of large allocations which
consume the memory.
Example output:
Page spans:
index size [B] free [B] large [B] [spans]
0 4096 4096 4096 1
1 8192 32768 0 0
2 16384 16384 0 0
3 32768 98304 2785280 85
4 65536 65536 1900544 29
5 131072 524288 471597056 3598
...
31 8796093022208 0 0 0
Large allocations: 484675584 [B]
Message-Id: <1548956406-7601-1-git-send-email-tgrabiec@scylladb.com>
Commit 976324bbb8 changed to use
get_application_state_ptr to get a pointer of the application_state. It
may return nullptr that is dereferenced unconditionally.
In resharding_test.py:ReshardingTest_nodes4_with_SizeTieredCompactionStrategy.resharding_by_smp_increase_test, we saw:
4 nodes in the tests
n1, n2, n3, n4 are started
n1 is stopped
n1 is changed to use different shard config
n1 is restarted ( 2019-01-27 04:56:00,377 )
The backtrace happened on n2 right fater n1 restarts:
0 INFO 2019-01-27 04:56:05,175 [shard 0] gossip - Feature STREAM_WITH_RPC_STREAM is enabled
1 INFO 2019-01-27 04:56:05,175 [shard 0] gossip - Feature WRITE_FAILURE_REPLY is enabled
2 INFO 2019-01-27 04:56:05,175 [shard 0] gossip - Feature XXHASH is enabled
3 WARN 2019-01-27 04:56:05,177 [shard 0] gossip - Fail to send EchoMessage to 127.0.58.1: seastar::rpc::closed_error (connection is closed)
4 INFO 2019-01-27 04:56:05,205 [shard 0] gossip - InetAddress 127.0.58.1 is now UP, status =
5 Segmentation fault on shard 0.
6 Backtrace:
7 0x00000000041c0782
8 0x00000000040d9a8c
9 0x00000000040d9d35
10 0x00000000040d9d83
11 /lib64/libpthread.so.0+0x00000000000121af
12 0x0000000001a8ac0e
13 0x00000000040ba39e
14 0x00000000040ba561
15 0x000000000418c247
16 0x0000000004265437
17 0x000000000054766e
18 /lib64/libc.so.6+0x0000000000020f29
19 0x00000000005b17d9
We do not know when this backtrace happened, but according to log from n3 an n4:
INFO 2019-01-27 04:56:22,154 [shard 0] gossip - InetAddress 127.0.58.2 is now DOWN, status = NORMAL
INFO 2019-01-27 04:56:21,594 [shard 0] gossip - InetAddress 127.0.58.2 is now DOWN, status = NORMAL
We can be sure the backtrace on n2 happened before 04:56:21 - 19 seconds (the
delay the gossip notice a peer is down), so the abort time is around 04:56:0X.
The migration_manager::maybe_schedule_schema_pull that triggers the backtrace
must be scheduled before n1 is restarted, because it dereference
application_state pointer after it sleeps 60 seconds, so the time
maybe_schedule_schema_pull is called is around 04:55:0X which is before n1 is
restarted.
So my theory is: migration_manager::maybe_schedule_schema_pull is scheduled, at this time
n1 has SCHEMA application_state, when n1 restarts, n2 gets new application
state from n1 which does not have SCHEMA yet, when migration_manager::maybe_schedule
wakes up from the 60 sleep, n1 has non-empty endpoint_state but empty
application_state for SCHEMA. We dereference the nullptr
application_state and abort.
Fixes: #4148
Tests: resharding_test.py:ReshardingTest_nodes4_with_SizeTieredCompactionStrategy.resharding_by_smp_increase_test
Message-Id: <9ef33277483ae193a49c5f441486ee6e045d766b.1548896554.git.asias@scylladb.com>
When a repair failed, we saw logs like:
repair - Checksum of range (8235770168569320790, 8235957818553794560] on
127.0.0.1 failed: std::bad_alloc (std::bad_alloc)
It is hard to tell which keyspace and table has failed.
To fix, log the keyspace and table name. It is useful to know when debugging.
Fixes#4166
Message-Id: <8424d314125b88bf5378ea02a703b0f82c2daeda.1548818669.git.asias@scylladb.com>
Stop calling .remove_suffix on empty string_view.
ck_bview can be empty because this function can be
called for a half open range tombstone.
It is impossible to write such range tombstones to LA/KA SSTables
so we should throw a proper exception instead of allowing
an undefined behaviour.
Refs #4113
Tests: unit(release)
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Message-Id: <c3738916953e4b10812aed95e645c739b4c29462.1548777086.git.piotr@scylladb.com>
All of our python scripts are there and they are all installed
automatically into /usr/lib/scylla. By keeping scylla-housekeeping
separately we are just complicating our build process.
This would be just a minor annoyance but this broke the new relocatable
process for python3 that I am trying to put together because I forgot to
add the new location as a source for the scripts.
Therefore, I propose we start being more diligent with this and keeping
all scripts together for the future.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
Message-Id: <20190123191732.32126-2-glauber@scylladb.com>
When a file in the `seastar` directory changes, we want to minimize the
amount of Scylla artifacts that are re-built while ensuring that all
changes in Seastar are reflected in Scylla correctly.
For compiling object files, we change Seastar to be an "order only"
dependency so that changes to Seastar don't trigger unnecessary builds.
For linking, we add an "implicit" dependency on Seastar so that Scylla
is re-linked when Seastar changes.
With these changes, modifying a Seastar header file will trigger the
recompilation of the affected Scylla object files, and modifying a
Seastar source file will trigger linking only.
Fixes#4171
Signed-off-by: Jesse Haber-Kucharsky <jhaberku@scylladb.com>
Message-Id: <0ab43d79ce0d41348238465d1819d4c937ac6414.1548906335.git.jhaberku@scylladb.com>
Fully expired sstable is not added to compacting set, meaning it's not actually
compacted, but it's kept in a list of sstables which incremental compaction
uses to check if any sstable can be replaced.
Incremental compaction was unconditionally removing expired sstable from compacting
set, which led to segfault because end iterator was given.
The fix is about changing sstable_set::erase() behavior to follow standard one
for erase functions which will works if the target element is not present.
Fixes#4085.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20190130163100.5824-1-raphaelsc@scylladb.com>
"
This series enhances perf_simple_query error reporting by adding an
option of producing a json file containing the results. The format of
that file is very similar to the results produces by perf_fast_forward
in order to ease integration with any tools that may want to interpret
them.
In addition to that perf_simple_query now prints to the standard output
median, median absolute deviation, minimum and maximum of the partial
results, so that there is no need for external scripts to compute those
values.
"
* tag 'perf_simple_query-json/v1' of https://github.com/pdziepak/scylla:
perf_simple_query: produce json results
perf_simple_query: calculate and print statistics
perf: time_parallel: return results of each iteration
perf_simple_query: take advantage of threads in main()
"
Recently it was discovered that the memtable reader
(partition_snapshot_reader to be more precise) can violate mutation
fragment monotonicity, by remitting range tombstones when those overlap
with more than one ck range of the partition slice.
This was fixed by 7049cd9, however after that fix was merged a much
simpler fix was proposed by Tomek, one that doesn't involve nearly as
much changes to the partition snapshot reader and hences poses less risk
of breaking it.
This mini-series reverts the previous fix, then applies the new, simpler
one.
Refs: #4104
"
* 'partition-snapshot-reader-simpler-fix/v2' of https://github.com/denesb/scylla:
partition_snapshot_reader: don't re-emit range tombstones overlapping multiple ck ranges
Revert "partition_snapshot_reader: don't re-emit range tombstones overlapping multiple ck ranges"
Committer: Avi Kivity <avi@scylladb.com>
Branch: next
Switch to the the CMake-ified Seastar
This change allows Scylla to be compiled against the `master` branch of
Seastar.
The necessary changes:
- Add `-Wno-error` to prevent a Seastar warning from terminating the
build
- The new Seastar build system generates the pkg-config files (for
example, `seastar.pc`) at configure time, so we don't need to invoke
Ninja to generate them
- The `-march` argument is no longer inherited from Seastar (correctly),
so it needs to be provided independently
- Define `SEASTAR_TESTING_MAIN` so that the definition of an entry
point is included for all unit test compilation units
- Independently link Scylla against Seastar's compiled copy of fmt in
its build directory
- All test files use the (now public) Seastar testing headers
- Add some missing Seastar headers to source files
[avi: regenerate frozen toolchain, adjust seastar submoule]
Signed-off-by: Jesse Haber-Kucharsky <jhaberku@scylladb.com>
Message-Id: <02141f2e1ecff5cbcd56b32768356c3bf62750c4.1548820547.git.jhaberku@scylladb.com>
When entering a new ck range (of the partition-slice), the partition
snapshot reader will apply to its range tombstones stream all the
tombstones that are relevant to the new ck range. When the partition has
range tombstones that overlap with multiple ck ranges, these will be
applied to the range tombstone stream when entering any of the ck ranges
they overlap with. This will result in the violation of the monotonicity
of the mutation fragments emitted by the reader, as these range
tombstones will be re-emitted on each ck range, if the ck range has at
least one clustering row they apply to.
For example, given the following partition:
rt{[1,10]}, cr{1}, cr{2}, cr{3}...
And a partition-slice with the following ck ranges:
[1,2], [3, 4]
The reader will emit the following fragment stream:
rt{[1,10]}, cr{1}, cr{2}, rt{[1,10]}, cr{3}, ...
Note how the range tombstone is emitted twice. In addition to violating
the monotonicity guarantee, this can also result in an explosion of the
number of emitted range tombstones.
Fix by trimming range tombstones to the start of the current ck range,
thus ensuring that they will not violate mutation fragment monotonicity
guarantees.
Refs: #4104
This is a much simpler fix for the above issue, than the already
committed one (7049cd937A). The latter is reverted by the previous
patch and this patch applies the simpler fix.
docs/metrics.md so far explained just the REST API for retrieving current
metrics from a single Scylla node. In this patch, I add basic explanations
on how to use the Prometheus and Grafana tools included in the
"scylla-grafana-monitoring" project.
It is true that technically, what is being explained here doesn't come
with the Scylla project and requires the separate scylla-grafana-monitoring
to be installed as well. Nevertheless, most Scylla developers will need this
knowledge eventually and suprisingly it appears it was never documented
anywhere accessible to newbie developers, and I think metrics.md is the
right place to introduce it.
In fact, I myself wasn't aware until today that Prometheus actually had
its own Web UI on port 9090, and that it is probably more useful for
developers than Grafana is.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Reviewed-by: Botond Denes <bdenes@scylladb.com>
Message-Id: <20190129114214.17786-1-nyh@scylladb.com>
"
An error in validating CONTAINS restrictions against collections caused
only the first restriction to be taken into account due to returning
prematurely.
This miniseries provides a fix for that as well as a matching test case.
Tests: unit (release)
Fixes#4161
"
* 'fix_multiple_contains_for_one_column' of https://github.com/psarna/scylla:
tests: enable CONTAINS tests for filtering
cql3: remove premature return from is_satisfied_by
cql3: restore indentation
Tests for filtering with CONTAINS restrictions were not enabled,
so they are now. Also, another case for having two CONTAINS restrictions
for a single column is added.
Refs #4161
Function which checked whether a CONTAINS restriction is satisfied
by a collection erroneously returned prematurely after checking
just the first restriction - which works fine for the usual case,
but fails if there are multiple CONTAINS restrictions present
for a column.
Fixes#4161
The value is already passed by cql_table_large_partition_handler, so
the default was just for nop_large_partition_handler.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
For reporting large rows we have to be able to print clustering keys
in addition to partition keys.
Refs #3988.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
Use the ":z" suffix to tell Docker to relabel file objets on shared
volumes. Fixes accessing filesystem via dbuild when SELinux is enabled.
Message-Id: <20190128160557.2066-1-penberg@scylladb.com>
"
Cleanup of temporary sstable directories in distributed_loader::populate_column_family
is completely broken and non tested. This code path was never executed since
populate_column_family doesn't currently list subdirectories at all.
This patchset fixes this code path and scans subdirectories in populate_column_family.
Also, a unit test is added for testing the cleanup of incomplete (unsealed) sstables.
Fixes: #4129
"
* 'projects/sst-temp-dir-cleanup/v3' of https://github.com/bhalevy/scylla:
tests: add test_distributed_loader_with_incomplete_sstables
tests: single_node_cql_env::do_with: use the provided data_file_directories path if available
tests: single_node_cql_env::_data_dir is not used
distributed_loader: populate_column_family should scan directories too
sstables: fix is_temp_dir
distributed_loader: populate_column_family: ignore directories other than sstable::is_temp_dir
distributed_loader: remove temporary sstable directories only on shard 0
distributed_loader: push future returned by rmdir into futures vector
"
This series prevents view building to fall back to storing hints.
Instead, it will try to send hints to an endpoint as if it has
consistency level ONE, and in case of failure retry the whole
building step. Then, view building will never be marked as finished
prematurely (because of pending hints), which will help avoid
creating inconsistencies when decommissioning a node from the cluster.
Tests:
unit (release)
dtest (materialized_views_test.py.*)
Fixes#3857Fixes#4039
"
* 'do_not_mark_view_as_built_with_hints_7' of https://github.com/psarna/scylla:
db,view: add updating view_building_paused statistics
database: add view_building_paused metrics
table: make populate_views not allow hints
db,view: add allow_hints parameter to mutate_MV
storage_proxy: add allow_hints parameter to send_to_endpoint
View building uses populate_views to generate and send view updates.
This procedure will now not allow hints to be used to acknowledge
the write. Instead, the whole building step will be retried on failure.
Fixes#3857Fixes#4039
Despite the name, this option also controls if a warning is issued
during memtable writes.
Warning during memtable writes is useful but the option name also
exists in cassandra, so probably the best we can do is update the
description.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
Message-Id: <20190125020821.72815-1-espindola@scylladb.com>
We need to follow changes of rpm package build procedure on
-jmx/-tools/-ami packages, since it have been changed when we merged
relocatable pacakge.
Signed-off-by: Takuya ASADA <syuu@scylladb.com>
Message-Id: <20190127204436.13959-1-syuu@scylladb.com>
On Scylla 3rdparty tools, we add /opt/scylladb/lib to LD_LIBRARY_PATH.
We use same directory for relocatable binaries, including libc.so.6.
Once we install both scylla-env package and relocatable version of scylla-server package, the loader tries to load libc from /opt/scylladb/lib then entire distribution become unusable.
We may able to use Obsoletes or Conflict tag on .rpm/.deb to avoid
install new Scylla package with scylla-env, but it's better & safer not to share
same directory for different purpose.
Fixes#3943
Signed-off-by: Takuya ASADA <syuu@scylladb.com>
Message-Id: <20190128023757.25676-1-syuu@scylladb.com>
Make it easier to work interactively by not reporting surprising times.
There are also reports that dtest fails with incorrect timezones, but those
are probably bugs in dtest.
Message-Id: <20190127134754.1428-1-avi@scylladb.com>
Test removal of sstables with temporary TOC file,
with and without temporary sstable directory.
Temporary sstable directories may be empty or still have
leftover components in them.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
