Query options need to have correct _value_views in order to
get_value_at() to work. With this patch we switch to constructor that
generates value views from the passed values and sets remaining options
to their default values.
Signed-off-by: Paweł Dziepak <pdziepak@cloudius-systems.com>
Read-ahead will require that we close input_streams. As part of that
we have to close sstables, and mutation_readers (which encapsulate
input_streams). This is part 1 of a patchset series to do that.
(The overarching goal is to enable read-ahead for sstables, see #244)
Conflicts:
sstables/compaction.cc
"Initial implementation/transposition of commit log replay.
* Changes replay position to be shard aware
* Commit log segment ID:s now follow basically the same scheme as origin;
max(previous ID, wall clock time in ms) + shard info (for us)
* SStables now use the DB definition of replay_position.
* Stores and propagates (compaction) flush replay positions in sstables
* If CL segments are left over from a previous run, they, and existing
sstables are inspected for high water mark, and then replayed from
those marks to amend mutations potentially lost in a crash
* Note that CPU count change is "handled" in so much that shard matching is
per _previous_ runs shards, not current.
Known limitations:
* Mutations deserialized from old CL segments are _not_ fully validated
against existing schemas.
* System::truncated_at (not currently used) does not handle sharding afaik,
so watermark ID:s coming from there are dubious.
* Mutations that fail to apply (invalid, broken) are not placed in blob files
like origin. Partly because I am lazy, but also partly because our serial
format differs, and we currently have no tools to do anything useful with it
* No replay filtering (Origin allows a system property to designate a filter
file, detailing which keyspace/cf:s to replay). Partly because we have no
system properties.
There is no unit test for the commit log replayer (yet).
Because I could not really come up with a good one given the test
infrastructure that exists (tricky to kill stuff just "right").
The functionality is verified by manual testing, i.e. running scylla,
building up data (cassandra-stress), kill -9 + restart.
This of course does not really fully validate whether the resulting DB is
100% valid compared to the one at k-9, but at least it verified that replay
took place, and mutations where applied.
(Note that origin also lacks validity testing)"
Fixes#98.
Using a lambda for implementing a mutation_reader is nifty, but does not
allow us to add methods.
Switch to a class-based implementation in anticipation of adding a close()
method.
Read-ahead requires input_streams to be closed, so add a close() method
to random_access_reader() and use it.
We don't yet call actually input_stream::close(), because that is not yet
merged; this patch lays the groundwork.
* Make it more like origin, i.e. based on wall clock time of app start
* Encode shard ID in the, RP segement ID, to ensure RP:s and segement names
are unique per shard
Origin
* Note: removed commitlog_test:test_allocation_failure because with
segments limited to 4GB -> mutation limited to 2GB, actually forcing
a fail is not guaranteed or even likely.
"I saw about 4% improvement in perf_sstable write on muninn with this. The
decorated_key comparison is gone from the perf profile now. Now most of the
work inside the reader is for copying the mutation."
