We don't pull schema during rolling upgrade, that is until
schema_tables_v3 feature is enabled on all nodes.
Because features are enabled from gossiper timer, there is a race
between feature enablement and processing of endpoint states which may
trigger schema pull. It can happen that we first try to pull, but
only later enable the feature. In that case the schema pull will not
happen until the next schema change.
The fix is to ensure that pulls abandoned due to feature not being enabled
will be retried when it is enabled.
Fixes sporadic failure in dtest:
repair_additional_test.py:RepairAdditionalTest.repair_schema_test
Message-Id: <1506428715-8182-2-git-send-email-tgrabiec@scylladb.com>
Since commit 8378fe190, we disable schema sync in a mixed cluster.
The detection is done using gossiper features. We need to make sure
the features are registerred, and thus can be enabled, before the
bootstrapping of a non-seed node happens. Otherwise the bootstrap will
hang waiting on schema sync which will not happen.
Message-Id: <1505893837-27876-2-git-send-email-tgrabiec@scylladb.com>
This is another place we can update endpoint_state_map in addition to
gossiper::run().
Call the gossiper:maybe_enable_features() so that we won't miss gossip
feature update.
The current sequential scan can take a long time on a small or empty table
with a large (nr_nodes * nr_vnodes) count, and can time out. Switching to
exponential scan reduces the time.
Fixes#1230.
Message-Id: <20170912173803.8277-1-avi@scylladb.com>
If there is a schema pull during rolling upgrade among a two 2.0 nodes,
then schema merge will delete the persisted schema version. When the node
loads that table again, e.g. on restart, it will generate a version
which is different than the one which 1.7 nodes use. This will
cause reads and writes to fail.
To avoid this, disable pulls until all nodes are upgraded.
Fixes#2802.
Collect coordinator side read statistic per CF and use them in percentile
speculative read executor. Getting percentile from estimated_histogram
object is rather expensive, so cache it and recalculate only once per
second (or if requested percentile changes).
Fixes#2757
Message-Id: <20170911131752.27369-3-gleb@scylladb.com>
A keyspace can be deleted while write is ongoing, so the object cannot
be used after defer point. The keyspace reference is only used to check
how many replies a write operation should wait for and this can be
precalculated during write handler creation.
Fixes#2777
Message-Id: <20170911084436.GG24167@scylladb.com>
Scylla 1.7.4 used incorrect ordering of counter shards. In order to fix
this problem a new feature is introduced that will be used to determine
when nodes with that bug fixed can start sending counter shard in the
correct order.
"Now that range queries go through the normal digest path, we rely on
query::result::calculate_counts() to count the amount of partitions
and rows returned.
This series optimizes it, in case it is needed, and also changes the
result message to include the partition and row counts, avoiding the
calculation altogether."
* 'calculate-counts/v3' of github.com:duarten/scylla:
query-result: Send row and partition count over the wire
query::result: Optimize calculate_counts()
Now that range queries go through the normal digest path, we rely on
query::result::calculate_counts() to count the amount of partitions
and rows returned. This patch makes it a bit faster.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
Now that we don't go directly to reconciliation for range queries, the
result isn't required to have the row and partition counts calculated
(we no longer transform a reconciled_result to a query::result).
Furthermore, this line was causing a lot of dtests to fail on account
of them not expecting an error line in the logs.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
Message-Id: <20170810225351.12610-1-duarte@scylladb.com>
Currently scanning reads go to reconciliation stage directly which
requires asking for mutation data from all peers. This patch makes
it to try matching digests first like a single partition read.
The change requires internode protocol changes since currently it is not
possible to ask for multi partition data/digest over RPC. It means that
the capability has to be guarded by new gossip feature flag which the
patch also adds.
never_speculating_read_executor always waits for all targets so
block_for parameter is always equal to targets.size(). No need to
to pass it explicitly.
If schema merging completes at lower rate than incoming pull requests,
then merge processes will accumulate and needlessly request and hold schema mutations.
In rare cases, when there are constant schema changes, they may even
overflow memory. This was seen in dtest:
concurrent_schema_changes_test.py:TestConcurrentSchemaChanges.create_lots_of_schema_churn_test
Allowing only one active and one queued pull request per remote
endpoint is enough.
Initialize the system_auth and system_traces keyspaces and their tables after
the Node joins the token ring because as a part of system_auth initialization
there are going to be issues SELECT and possible INSERT CQL statements.
This patch effectively reverts the d3b8b67 patch and brings the initialization order
to how it was before that patch.
Fixes#2273
Signed-off-by: Vlad Zolotarov <vladz@scylladb.com>
Message-Id: <1500417217-16677-1-git-send-email-vladz@scylladb.com>
Some places remained where code looked directly at
system_keyspace::NAME to determine iff a ks is
considered special/system/protected. Including
schema digest calculation.
Export "is_system_keyspace" and use accordingly.
Message-Id: <1500469809-23546-1-git-send-email-calle@scylladb.com>
In storage_proxy we arrange the mutations sent by the replicas in a
vector of vectors, such that each row corresponds to a partition key
and each column contains the mutation, possibly empty, as sent by a
particular replica.
There is reconciliation-related code that assumes that all the
mutations sent by a particular replica can be found in a single
column, but that isn't guaranteed by the way we initially arrange the
mutations.
This patch fixes this and enforces the expected order.
Fixes#2531Fixes#2593
Signed-off-by: Gleb Natapov <gleb@scylladb.com>
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
Message-Id: <20170713162014.15343-1-duarte@scylladb.com>
The old nodes which are still using v2 schema tables will fail to
apply our response, with error messages complaining about not being
able to locate schema of certain versions (new schema tables). This
change inhibits such errors by responding with an empty mutation list.
Currently it results in scary error messages in logs about not being
able to find schema of given version. It's benign, but may scare
users. It the future incompatibilities could result in more subtle
errors. Better to inhibit it completely.
This will allow expressing lack of information about certain ranges of
rows (including the static row), which will be used in cache to
determine if information in cache is complete or not.
Continuity is represented internally using flags on row entries. The
key range between two consecutive entries is continuous iff
rows_entry::continuous() is true for the later entry. The range
starting after the last entry is assumed to be continuous. The range
corresponding to the key of the entry is continuous iff
rows_entry::dummy() is false.
[tgrabiec:
- based on the following commits:
4a5bf75 - Piotr Jastrzebski : mutation_partition: introduce dummy rows_entry
773070e - Piotr Jastrzebski : mutation_partition: add continuity flag to rows_entry
- documented that partition tombstone is always complete
- require specifying the partition tombstone when creating an incomplete entry
- replaced rows_entry(dummy_tag, ...) constructor with more general
rows_entry(position_in_partition, ...)
- documented continuity semantics on mutation_partition
- fixed _static_row_cached being lost by mutation_partition copy constructors
- fixed conversion to streamed_mutation to ignore dummy entries
- fixed mutation_partition serializer to drop dummy entries
- documented semantics of continuity on mutation_partition level
- dropped assumptions that dummy entries can be only at the last position
- changed equality to ignore continuity completely, rather than
partially (it was not ignoring dummy entries, but ignoring
continuity flag)
- added printout of continuity information in mutation_partition
- fixed handling of empty entries in apply_reversibly() with regards
to continuity; we no longer can remove empty entries before
merging, since that may affect continuity of the right-hand
mutation. Added _erased flag.
- fixed mutation_partition::clustered_row() with dummy==true to not ignore the key
- fixed partition_builder to not ignore continuity
- renamed dummy_tag_t to dummy_tag. _t suffix is reserved.
- standardized all APIs on is_dummy and is_continuous bool_class:es
- replaced add_dummy_entry() with ensure_last_dummy() with safer semantics
- dropped unused remove_dummy_entry()
- simplified and inlined cache_entry::add_dummy_entry()
- fixed mutation_partition(incomplete_tag) constructor to mark all row ranges as discontinuous
]
The code filters CFs by name to not include system keyspace, but v3
schema added yet another system namespace. Better filter according to
replication strategy to accommodate for schema v4 adding even more
system keyspaces.
Fixes: #2516
Message-Id: <20170621073816.GB3944@scylladb.com>
Boost 1.55 (ubuntu 14) fails to compile because an iterator produce by
boost::adaptors::transformed() when std::ref to lambda is passed to
it do not match iterator concept. It cannot be default constructed
because std::reference_wrapper is not default constructable.
boost::range::min_element() never actually default construct it, but
concept is checked anyway. The patch fixes it by providing an explicit
functor that is default constructable.
Message-Id: <20170618131836.GD3944@scylladb.com>
When making the schema mutations for a view update, we should only
include the base table schema mutations (in case the target node
doesn't contain them) when the view is being directly updated. When it
is being updated as a side effect of updating the base table, then
including the base schema mutations will hide the actual changes being
performed on the base.
Fixes#2500
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
Message-Id: <1497782822-2711-1-git-send-email-duarte@scylladb.com>
This patch makes storage proxy to choose replicas to read from base on
their cache hit rates. Replicas with higher cache hit rates will see
more requests while replicas with lower hit rates will see less. Local
node has a special bonus and will get more requests even if another node
has slightly higher cache hit rate (same goes for local vs remote DC),
but after the patch it is no longer guarantied that a coordinator node
will be chosen as a replica for the read (if the feature is enabled).
Currently storage proxy has to loop over remaining replicas to search
for suitable extra replica, but doing it in filter_for_query() is
extremely easy, so do it there instead.
When a node start it does not have any information about cache temperature
of other nodes in the cluster and it is hard (if not impossible) to make
right guess. During cluster startup all nodes have cold caches, so there
is no point to redirect reads to other nodes even though local cache it
cold, but if only that node restarted than other nodes have populated
cache and reads should be redirected.
The node will get up-to-date information about other nodes caches,
but only after receiving first reply, until then it does not have the
information to make right decisions which may cause unwanted spikes
immediately after restart. Having cache temperature in gossiper helps
to solve the problem.
This patch adds new class cache_hitrate_calculator whose responsibility
is to periodically calculate average cache hit rates between all shards
for each CF.
