Fixes a build failure when only the scylla binary was selected for
building like this:
./configure.py --with scylla
In this case the rule for gen_crc_combine_table was missing, but it is
needed to build crc_combine_table.o
Message-Id: <1544010138-21282-1-git-send-email-tgrabiec@scylladb.com>
(cherry picked from commit edbef7400b)
gen_crc_combine_table is now executed on every build, so it should not
fail on unsupported archs. The generated file will not contain data,
but this is fine since it should not be used.
Another problem is that u32 and u64 aliases were not visible in the #else
branch in crc_combine.cc
Message-Id: <1543864425-5650-1-git-send-email-tgrabiec@scylladb.com>
(cherry picked from commit 9a4c00beb7)
"
zlib's crc32_combine() is not very efficient. It is faster to re-combine
the buffer using crc32(). It's still substantial amount of work which
could be avoided.
This patch introduces a fast implementation of crc32_combine() which
uses a different algorithm than zlib. It also utilizes intrinsics for
carry-less multiplication instruction to perform the computation faster.
The details of the algorithm can be found in code comments.
Performance results using perf_checksum and second buffer of length 64 KiB:
zlib CRC32 combine: 38'851 ns
libdeflate CRC32: 4'797 ns
fast_crc32_combine(): 11 ns
So the new implementation is 3500x faster than zlib's, and 417x faster than
re-checksumming the buffer using libdeflate.
Tested on i7-5960X CPU @ 3.00GHz
Performance was also evaluated using sstable writer benchmark:
perf_fast_forward --populate --sstable-format=mc --data-directory /tmp/perf-mc \
--value-size=10000 --rows 1000000 --datasets small-part
It yielded 9% improvement in median frag/s (129'055 vs 117'977).
Refs #3874
"
* tag 'fast-crc32-combine-v2' of github.com:tgrabiec/scylla:
tests: perf_checksum: Test fast_crc32_combine()
tests: Rename libdeflate_test to checksum_utils_test
tests: libdeflate: Add more tests for checksum_combine()
tests: libdeflate: Check both libdeflate and default checksummers
sstables: Use fast_crc_combine() in the default checksummer
utils/gz: Add fast implementation of crc32_combine()
utils/gz: Add pre-computed polynomials
utils/gz: Import Barett reduction implementation from libdeflate
utils: Extract clmul() from crc.hh
(cherry picked from commit b098b5b987)
"
One part of the improvement comes from replacing zlib's CRC32 with the one
from libdeflate, which is optimized for modern architecture and utilizes the
PCLMUL instruction.
perf_checksum test was introduced to measure performance of various
checksumming operations.
Results for 514 B (relevant for writing with compression enabled):
test iterations median mad min max
crc_test.perf_deflate_crc32_combine 58414 16.711us 3.483ns 16.708us 16.725us
crc_test.perf_adler_combine 165788278 6.059ns 0.031ns 6.027ns 7.519ns
crc_test.perf_zlib_crc32_combine 59546 16.767us 26.191ns 16.741us 16.801us
---
crc_test.perf_deflate_crc32_checksum 12705072 83.267ns 4.580ns 78.687ns 98.964ns
crc_test.perf_adler_checksum 3918014 206.701ns 23.469ns 183.231ns 258.859ns
crc_test.perf_zlib_crc32_checksum 2329682 428.787ns 0.085ns 428.702ns 510.085ns
Results for 64 KB (relevant for writing with compression disabled):
test iterations median mad min max
crc_test.perf_deflate_crc32_combine 25364 38.393us 17.683ns 38.375us 38.545us
crc_test.perf_adler_combine 169797143 5.842ns 0.009ns 5.833ns 6.901ns
crc_test.perf_zlib_crc32_combine 26067 38.663us 95.094ns 38.546us 40.523us
---
crc_test.perf_deflate_crc32_checksum 202821 4.937us 14.426ns 4.912us 5.093us
crc_test.perf_adler_checksum 44684 22.733us 206.263ns 22.492us 25.258us
crc_test.perf_zlib_crc32_checksum 18839 53.049us 36.117ns 53.013us 53.274us
The new CRC32 implementation (deflate_crc32) doesn't provide a fast
checksum_combine() yet, it delegates to zlib so it's as slow as the latter.
Because for CRC32 checksum_combine() is several orders of magnitude slower
than checksum(), we avoid calling checksum_combine() completely for this
checksummer. We still do it for adler32, which has combine() which is faster
than checksum().
SStable write performance was evaluated by running:
perf_fast_forward --populate --data-directory /tmp/perf-mc \
--rows=10000000 -c1 -m4G --datasets small-part
Below is a summary of the average frag/s for a memtable flush. Each result is
an average of about 20 flushes with stddev of about 4k.
Before:
[1] MC,lz4: 330'903
[2] LA,lz4: 450'157
[3] MC,checksum: 419'716
[4] LA,checksum: 459'559
After:
[1'] MC,lz4: 446'917 ([1] + 35%)
[2'] LA,lz4: 456'046 ([2] + 1.3%)
[3'] MC,checksum: 462'894 ([3] + 10%)
[4'] LA,checksum: 467'508 ([4] + 1.7%)
After this series, the performance of the MC format writer is similar to that
of the LA format before the series.
There seems to be a small but consistent improvement for LA too. I'm not sure
why.
"
* tag 'improve-mc-sstable-checksum-libdeflate-v3' of github.com:tgrabiec/scylla:
tests: perf: Introduce perf_checksum
tests: Add test for libdeflate CRC32 implementation
sstables: compress: Use libdeflate for crc32
sstables: compress: Rename crc32_utils to zlib_crc32_checksummer
licenses: Add libdeflate license
Integrate libdeflate with the build system
Add libdeflate submodule
sstables: Avoid checksum_combine() for the crc32 checksummer
sstables: compress: Avoid unnecessary checksum_combine()
sstables: checksum_utils: Add missing include
(cherry picked from commit 5e759b0c07)
Both of these have the same problem. They remove the to-be-evicted
entries from `_entries` but they don't unregister the `entry` from the
`read_concurrency_semaphore`. This results in the
`reader_concurrency_semaphore` being left with a dangling pointer to the
entries will trigger segfault when it tries to evict the associated
inactive reads.
Also add a unit test for `evict_all_for_table()` to check that it works
properly (`evict_one()` is only used in tests, so no dedicated test for
it).
Fixes: #3962
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <57001857e3791c6385721b624d33b667ccda2e7d.1544010868.git.bdenes@scylladb.com>
(cherry picked from commit 77dbc7d09a)
Current code assumes that request failed if all replicas replied with
failure, but this is not true for CL=ANY requests. Take it into account.
Fixed: #3565
(cherry picked from commit 17197fb005)
Currently if write request reaches CL and all replicas replied, but some
replied with failures, the request will wait for timeout to be retired.
Detect this case and retire request immediately instead.
Fixes#3566
(cherry picked from commit d1d04eae3c)
Before accounting failure response we need to make sure it comes from a
replica that participates in the request.
(cherry picked from commit 76ab3d716b)
"
This series changes hinted handoff to work with `frozen_mutation`s
instead of naked `mutation`s. Instead of unfreezing a mutation from
the commitlog entry and then freezing it again for sending, now we'll
just keep the read, frozen mutation.
Tests: unit(release)
"
* 'hh-manager-cleanup/v1' of https://github.com/duarten/scylla:
db/hints/manager: Use frozen_mutation instead of mutation
db/hints/manager: Use database::find_schema()
db/commitlog/commitlog_entry: Allow moving the contained mutation
service/storage_proxy: send_to_endpoint overload accepting frozen_mutation
service/storage_proxy: Build a shared_mutation from a frozen_mutation
service/storage_proxy: Lift frozen_mutation_and_schema
service/storage_proxy: Allow non-const ranges in mutate_prepare()
(cherry picked from commit 1891779e64)
It is useful to have this counter to investigate the reason for read
repairs. Non zero value means that writes were lost after CL is reached
and RR is expected.
Message-Id: <20181009120900.GF22665@scylladb.com>
(cherry picked from commit 207b57a892)
write_stats is referenced from write handler which is available in
send_to_live_endpoints already. No need to pass it down.
Message-Id: <20181009133017.GA14449@scylladb.com>
(cherry picked from commit 319ece8180)
Remove the timeout argument to
db::view::view_builder::wait_until_built(), a test-only function to
wait until a given materialized view has finished building.
This change is motivated by the fact that some tests running on slow
environments will timeout. Instead of incrementally increasing the
timeout, remove it completely since tests are already run under an
exterior timeout.
Fixes#3920
Tests: unit release(view_build_test, view_schema_test)
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
Message-Id: <20181115173902.19048-1-duarte@scylladb.com>
(cherry picked from commit 6fbf792777)
mutate_MV usually calls send_to_endpoint() to push view update to remote
view replicas. This function gets passed a statistics object,
service::storage_proxy_stats::write_stats and, in particular, updates
its "writes" statistic which counts the number of ongoing writes.
In the case that the paired view replica happens to be the *same* node,
we avoid calling send_to_endpoint() and call mutate_locally() instead.
That function does not take a write_stats object, so the "writes" statistic
doesn't get incremented for the duration of the write. So we should do
this explicitly.
Co-authored-by: Nadav Har'El <nyh@scylladb.com>
Co-authored-by: Duarte Nunes <duarte@scylladb.com>
(cherry picked from commit 1d5f8d0015)
When the auth service is requested to stop during bootstrap,
it might have still not reached schema agreement.
Currently, waiting for this agreement is done in an infinite loop,
without taking abort_source into account.
This patch introduces checking if abort was requested
and breaking the loop in such case, so auth service can terminate.
Tests:
unit (release)
dtest (bootstrap_test.py:TestBootstrap.shutdown_wiped_node_cannot_join_test)
Message-Id: <1b7ded14b7c42254f02b5d2e10791eb767aae7fc.1543914769.git.sarna@scylladb.com>
(cherry picked from commit 7b0a3fbf8a)
Before this patch we were writing offset map enteies in unspecified
order, the one returned by std::unorderd_map. Cassandra writes them
sorted by metadata_type. Use the same order for improved
compatibility.
Fixes#3955.
Message-Id: <1543846649-22861-1-git-send-email-tgrabiec@scylladb.com>
(cherry picked from commit aa19f98d18)
"
This series attempts to solve the regressions recently discovered in
performance of multi-partition range-scans. Namely that they:
* Flood the reader concurrency semaphore's queues, trampling other
reads.
* Behave very badly when too many of them is running concurrently
(trashing).
* May deadlock if enough of them is running without a timeout.
The solution for these problems is to make inactive shard readers
evictable. This should address all three issues listed above, to varying
degrees:
* Shard readers will now not cling onto their permits for the entire
duration of the scan, which might be a lot of time.
* Will be less affected by infinite concurrency (more than the node can
handle) as each scan now can make progress by evicting inactive shard
readers belonging to other scans.
* Will not deadlock at all.
In addition to the above fix, this series also bundles two further
improvements:
* Add a mechanism to `reader_concurrecy_semaphore` to be notified of
newly inserted evictables.
* General cleanups and fixes for `multishard_combining_reader` and
`foreign_reader`.
I can unbundle these mini series and send them separately, if the
maintainers so prefer, altough considering that this series will have to
be backported to 3.0, I think this present form is better.
Fixes: #3835
"
* 'evictable-inactive-shard-readers/v7' of https://github.com/denesb/scylla: (27 commits)
tests/multishard_mutation_query_test: test stateless query too
tests/querier_cache: fail resource-based eviction test gracefully
tests/querier_cache: simplify resource-based eviction test
tests/mutation_reader_test: add test_multishard_combining_reader_next_partition
tests/mutation_reader_test: restore indentation
tests/mutation_reader_test: enrich pause-related multishard reader test
multishard_combining_reader: use pause-resume API
query::partition_slice: add clear_ranges() method
position_in_partition: add region() accessor
foreign_reader: add pause-resume API
tests/mutation_reader_test: implement the pause-resume API
query_mutations_on_all_shards(): implement pause-resume API
make_multishard_streaming_reader(): implement the pause-resume API
database: add accessors for user and streaming concurrency semaphores
reader_lifecycle_policy: extend with a pause-resume API
query_mutations_on_all_shards(): restore indentation
query_mutations_on_all_shards(): simplify the state-machine
multishard_combining_reader: use the reader lifecycle policy
multishard_combining_reader: add reader lifecycle policy
multishard_combining_reader: drop unnecessary `reader_promise` member
...
(cherry picked from commit 414b14a6bd)
So we don't attempt to send mutations to unreachable endpoints and
instead store a hint for them, we now check the endpoint status and
populate dead_endpoints accordingly in
storage_proxy::send_to_endpoint().
Fixes#3820
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
Message-Id: <20181007100640.2182-1-duarte@scylladb.com>
(cherry picked from commit 30d6ed8f92)
"
This patchset addresses two recently discovered bugs both triggered by
summary regeneration:
Tests: unit {release}
+
Validated with debug build of Scylla (ASAN) that no use-after-free
occurs when re-generating Summary.db.
"
* 'projects/sstables-30/summary-regeneration/v1' of https://github.com/argenet/scylla:
tests: Add test reading SSTables in 'mc' format with missing summary.
sstables: When loading, read statistics before summary.
database: Capture io_priority_class by reference to avoid dangling ref.
(cherry picked from commit 009cbd3dcb)
"
This series adds proper handling of filtering queries with LIMIT.
Previously the limit was erroneously applied before filtering,
which leads to truncated results.
To avoid that, paged filtering queries now use an enhanced pager,
which remembers how many rows dropped and uses that information
to fetch for more pages if the limit is not yet reached.
For unpaged filtering queries, paging is done internally as in case
of aggregations to avoid returning keeping huge results in memory.
Also, previously, all limited queries used the page size counted
from max(page size, limit). It's not good for filtering,
because with LIMIT 1 we would then query for rows one-by-one.
To avoid that, filtered queries ask for the whole page and the results
are truncated if need be afterwards.
Tests: unit (release)
"
* 'fix_filtering_with_limit_2' of https://github.com/psarna/scylla:
tests: add filtering with LIMIT test
tests: split filtering tests from cql_query_test
cql3: add proper handling of filtering with LIMIT
service/pager: use dropped_rows to adjust how many rows to read
service/pager: virtualize max_rows_to_fetch function
cql3: add counting dropped rows in filtering pager
(cherry picked from commit 1afda28cf3)
"
This miniseries ensures that system tables are not checked
for having view updates, because they never do.
What's more, distributed system table is used in the process,
so it's unsafe to query the table while streaming it.
Tests: unit (release), dtest(update_cluster_layout_tests.py:TestUpdateClusterLayout.simple_decommission_node_2_test)
"
* 'fix_checking_if_system_tables_need_view_updates_3' of https://github.com/psarna/scylla:
streaming: don't check view building of system tables
database: add is_internal_keyspace
streaming: remove unused sstable_is_staging bool class
(cherry picked from commit d09d4bbd91)
The reason for that is that it's not available in sstable format mc,
so we can no longer rely on it in common code for the currently
supported formats.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20181121170057.20900-1-raphaelsc@scylladb.com>
(cherry picked from commit d29482dce8)
"
Tested with perf_fast_forward from:
github.com/tgrabiec/scylla.git perf_fast_forward-for-sst3-opt-write-v1
Using the following command line:
build/release/tests/perf/perf_fast_forward_g --populate --sstable-format=mc \
--data-directory /tmp/perf-mc --rows=10000000 -c1 -m4G \
--datasets small-part
The average reported flush throughput was (stdev for the avergages is around 4k):
- for mc before the series: 367848 frag/s
- for lc before the series: 463458 frag/s (= mc.before +25%)
- for mc after the series: 429276 frag/s (= mc.before +16%)
- for lc after the series: 466495 frag/s (= mc.before +26%)
Refs #3874.
"
* tag 'sst3-opt-write-v2' of github.com:tgrabiec/scylla:
sstables: mc: Avoid serialization of promoted index when empty
sstables: mc: Avoid double serialization of rows
tests: sstable 3.x: Do not compare Statistics component
utils: Introduce memory_data_sink
schema: Optimize column count getters
sstables: checksummed_file_data_sink_impl: Bypass output_stream
(cherry picked from commit 4aa5d83590)
"
Enables sstable compression with LZ4 by default, which was the
long-time behavior until a regression turned off compression by
default.
Fixes#3926
"
* 'restore-default-compression/v2' of https://github.com/duarten/scylla:
tests/cql_query_test: Assert default compression options
compress: Restore lz4 as default compressor
tests: Be explicit about absence of compression
(cherry picked from commit bb85a21a8f)
Currently, when advance_and_await() fails to allocate the new gate
object, it will throw bad_alloc and leave the phased_barrier object in
an invalid state. Calling advance_and_await() again on it will result
in undefined behavior (typically SIGSEGV) beacuse _gate will be
disengaged.
One place affected by this is table::seal_active_memtable(), which
calls _flush_barrier.advance_and_await(). If this throws, subsequent
flush attempts will SIGSEGV.
This patch rearranges the code so that advance_and_await() has strong
exception guarantees.
Message-Id: <1542645562-20932-1-git-send-email-tgrabiec@scylladb.com>
Fixes#3931.
(cherry picked from commit 57e25fa0f8)
In (almost) all SSTable write paths, we need to inform the monitor that
the write has failed as well. The monitor will remove the SSTable from
controller's tracking at that point.
Except there is one place where we are not doing that: streaming of big
mutations. Streaming of big mutations is an interesting use case, in
which it is done in 2 parts: if the writing of the SSTable fails right
away, then we do the correct thing.
But the SSTables are not commited at that point and the monitors are
still kept around with the SSTables until a later time, when they are
finally committed. Between those two points in time, it is possible that
the streaming code will detect a failure and manually call
fail_streaming_mutations(), which marks the SSTable for deletions. At
that point we should propagate that information to the monitor as well,
but we don't.
Fixes#3732 (hopefully)
Tests: unit (release)
Signed-off-by: Glauber Costa <glauber@scylladb.com>
Message-Id: <20181114213618.16789-1-glauber@scylladb.com>
(cherry picked from commit 9f403334c8)
In commit a33f0d6, we changed the way we handle arrays during the write
and parse code to avoid reactor stalls. Some potentially big loops were
transformed into futurized loops, and also some calls to vector resizes
were replaced by a reserve + push_back idiom.
The latter broke parsing of the estimated histogram. The reason being
that the vectors that are used here are already initialized internally
by the estimated_histogram object. Therefore, when we push_back, we
don't fill the array all the way from index 0, but end up with a zeroed
beginning and only push back some of the elements we need.
We could revert this array to a resize() call. After all, the reason we
are using reserve + push_back is to avoid calling the constructor member
for each element, but We don't really expect the integer specialization
to do any of that.
However, to avoid confusion with future developers that may feel tempted
to converted this as well for the sake of consistency, it is safer to
just make sure these arrays are zeroed.
Fixes#3918
Signed-off-by: Glauber Costa <glauber@scylladb.com>
Message-Id: <20181116130853.10473-1-glauber@scylladb.com>
(cherry picked from commit c6811bd877)
After this patch, the Materialized Views and Secondary Index features
are considered generally-available and no longer require passing an
explicit "--experimental=on" flag to Scylla.
The "--experimental=on" flag and the db::config::check_experimental()
function remain unused, as we graduated the only two features which used
this flag. However, we leave the support for experimental features in
the code, to make it easier to add new experimental features in the future.
Another reason to leave the command-line parameter behind is so existing
scripts that still use it will not break.
Fixes#3917
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20181115144456.25518-1-nyh@scylladb.com>
(cherry picked from commit 78ed7d6d0c)
During streaming, there are cases when we should invoke the view write
path. In particular, if we're streaming because of repair or if a view
has not yet finished building and we're bootstrapping a new node.
The design constraints are:
1) The streamed writes should be visible to new writes, but the
sstable should not participate in compaction, or we would lose the
ability to exclude the streamed writes on a restart;
2) The streamed writes must not be considered when generating view
updates for them;
3) Resilient to node restarts;
4) Resilient to concurrent stream sessions, possibly streaming mutations for overlapping ranges.
We achieve this by writing the streamed writes to an sstable in a
different folder, call it "staging". We achieve 1) by publishing the
sstable to the column family sstable set, but excluding it from
compactions. We do these steps upon boot, by looking at the staging
directory, thus achieving 3).
Fixes#3275
* 'streaming_view_to_staging_sstables_9' of https://github.com/psarna/scylla: (29 commits)
tests: add materialized views test
tests: add view update generator to cql test env
main: add registering staging sstables read from disk
database: add a check if loaded sstable is already staging
database: add get_staging_sstable method
streaming: stream tables with views through staging sstables
streaming: add system distributed keyspace ref to streaming
streaming: add view update generator reference to streaming
main: add generating missed mv updates from staging sstables
storage_service: move initializing sys_dist_ks before bootstrap
db/view: add view_update_from_staging_generator service
db/view: add view updating consumer
table: add stream_view_replica_updates
table: split push_view_replica_updates
table: add as_mutation_source_excluding
table: move push_view_replica_updates to table.cc
database: add populating tables with staging sstables
database: add creating /staging directory for sstables
database: add sstable-excluding reader
table: add move_sstable_from_staging_in_thread function
...
(cherry picked from commit a38f6078fb)
On receiving a mutation_fragment or a mutation triggered by a streaming
operation, we pass an enum stream_reason to notify the receiver what
the streaming is used for. So the receiver can decide further operation,
e.g., send view updates, beyond applying the streaming data on disk.
Fixes#3276
Message-Id: <f15ebcdee25e87a033dcdd066770114a499881c0.1539498866.git.asias@scylladb.com>
(cherry picked from commit 7f826d3343)
"
It appears that in case when there are any static columns in serialization header,
Cassandra would write a (possibly empty) static row to every partition
in the SSTables file.
This patchset alings Scylla's logic with that of Cassandra.
Note that Scylla optimizes the case when no partition contains a static
row because it keeps track of updated columns that Scylla currently does
not do - see #3901 for details.
Fixes#3900.
"
* 'projects/sstables-30/write-all-static-rows/v1' of https://github.com/argenet/scylla:
tests: Test writing empty static rows for partitions in tables with static columns.
sstables: Ignore empty static rows on reading.
sstables: Write empty static rows when there are static columns in the table.
(cherry picked from commit 6469a1b451)
MC format lacks ancestors metadata, so we need to workaround it by using
ancestors in metadata collector, which is only available for a sstable
written during this instance. It works fine here because we only want
to know if a sstable recently compacted has an ancestor which wasn't
yet deleted.
Fixes#3852.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Reviewed-by: Vladimir Krivopalov <vladimir@scylladb.com>
Message-Id: <20181102154951.22950-1-raphaelsc@scylladb.com>
(cherry picked from commit 1c5934c934)
"
Use perftune.py for tuning disks:
- Distribute/pin disks' IRQs:
- For NVMe drives: evenly among all present CPUs.
- For non-NVMe drives: according to chosen tuning mode.
- For all disks used by scylla:
- Tune nomerges
- Tune I/O scheduler.
It's important to tune NIC and disks together in order to keep IRQ
pinning in the same mode.
Disk are detected and tuned based on the current content of
/etc/scylla/scylla.yaml configuration file.
"
Fixes#3831.
* 'use_perftune_for_disks-v3' of https://github.com/vladzcloudius/scylla:
dist: change the sysconfig parameter name to reflect the new semantics
scylla_util.py::sysconfig_parser: introduce has_option()
dist: scylla_setup and scylla_sysconfig_setup: change paremeters names to reflect new semantics
dist: don't distribute posix_net_conf.sh any more
dist: use perftune.py to tune disks and NIC
(cherry picked from commit f170e3e589)
* seastar 0c8a2c8...d6647df (3):
> scripts: perftune.py: properly merge parameters from the command line and the configuration file
> scripts: perftune.py: prioritize I/O schedulers
> Merge "scripts: perftune.py: support different I/O schedulers" from Vlad
Ref #3831.
This patchset addresses two issues with static rows support in SSTables
3.x. ('mc' format):
1. Since collections are allowed in static rows, we need to check for
complex deletion, set corresponding flag and write tombstones, if any.
2. Column indices need to be partitioned for static columns the same way
they are partitioned for regular ones.
* github.com/argenet/scylla.git projects/sstables-30/columns-proper-order-followup/v1:
sstables: Partition static columns by atomicity when reading/writing
SSTables 3.x.
sstables: Use std::reference_wrapper<> instead of a helper structure.
sstables: Check for complex deletion when writing static rows.
tests: Add/fix comments to
test_write_interleaved_atomic_and_collection_columns.
tests: Add test covering inverleaved atomic and collection cells in
static row.
(cherry picked from commit 62c7685b0d)
When a node reshards (i.e., restarts with a different number of CPUs), and
is in the middle of building a view for a pre-existing table, the view
building needs to find the right token from which to start building on all
shards. We ran the same code on all shards, hoping they would all make
the same decision on which token to continue. But in some cases, one
shard might make the decision, start building, and make progress -
all before a second shard goes to make the decision, which will now
be different.
This resulted, in some rare cases, in the new materialized view missing
a few rows when the build was interrupted with a resharding.
The fix is to add the missing synchronization: All shards should make
the same decision on whether and how to reshard - and only then should
start building the view.
Fixes#3890Fixes#3452
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20181028140549.21200-1-nyh@scylladb.com>
(cherry picked from commit b8337f8c9d)
