Will be used in row_cache_alloc_stress to unlink partitions which we
don't want to get evicted, instead of reapeatedly calling touch() on
them after each subsequent population. After switching to row-level
LRU, doing so greatly increases run time of the test due to quadratic
behavior.
Instead of evicting whole partitions, evicts whole rows.
As part of this, invalidation of partition entries was changed to not
evict from snapshots right away, but unlink them and let them be
evicted by the reclaimer.
We will need to propagate a cache_tracker reference to evict(). Instead
of evicting from destructor, do so before cache_entry gets unlinked
from the tree. Entries which are not linked, don't need to be
explicitly evicted.
Commit 6ccd317 introduced a bug in partition_entry::evict() where a
partition entry may be partially evicted if there are non-evictable
snapshots in it. Partially evicting some of the versions may violate
consistency of a snapshot which includes evicted versions. For one,
continuity flags are interpreted realtive to the merged view, not
within a version, so evicting from some of the versions may mark
reanges as continuous when before they were discontinuous. Also, range
tombtsones of the snapshot are taken from all versions, so we can't
partially evict some of them without marking all affected ranges as
discontinuous.
The fix is to revert back to full eviciton, and avoid moving
non-evictable snapshots to cache. When moving whole partition entry to
cache, we first create a neutral empty partition entry and then merge
the memtable entry into it just like we would if the entry already
existed.
Fixes#3215.
Tests: unit (release)
Message-Id: <1518710592-21925-2-git-send-email-tgrabiec@scylladb.com>
We have had a quota of partitions to process in clear_gently /
update_cache, so that we don't overwork. However, with those things now
being in their own task group there is no harm in allowing it to run
until we reach a natural preemption point.
While we are at it, clear_gently did not check for need_preempt()
before, so this patch fixes it.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
We have moved clear_gently from using a seastar::thread's scheduling_group to
using the CPU scheduler's. However, update_cache was forgotten.
This patch fixes that and gets rid of the old group just in case.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
In the last patch, we enabled per-request timeouts, we enable timeouts
in fill_buffer. There are many places, though, in which we
fast_forward_to before we fill_buffer, so in order to make that
effective we need to propagate the timeouts to fast_forward_to as well.
In the same way as fill_buffer, we make the argument optional wherever
possible in the high level callers, making them mandatory in the
implementations.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
As part of the work to enable per-request timeouts, we enable timeouts
in fill_buffer.
The argument is made optional at the main classes, but mandatory in all
the ::impl versions. This way we'll make sure we didn't forget anything.
At this point we're still mostly passing that information around and
don't have any entity that will act on those timeouts. In the next patch
we will wire that up.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
compiler: gcc (GCC) 6.3.1 20161221 (Red Hat 6.3.1-1)
Problems introduced in f6a461c7a4
and 37b19ae6ba, respectively.
They both fail to compile due to use of method in lambda without
explicit mention of this. Some of failure is fixed by not using
auto in lambda parameter.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20171218222144.12297-1-raphaelsc@scylladb.com>
and add read_context::enter_flat_partition. This will
temporarily coexist with read_context::enter_partition
but after everything in cache is migrated to flat reader
the new method will replace old one.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
If assignment to _lower_bound in the "_secondary_in_progress = true;"
case in do_read_from_primary() throws due to allocation failure, the
update section will be retried and we will take the not_moved path,
skipping the range which was discontinuous and was supposed to be read
from underlying.
Fix by redoing lookup using _lower_bound in case the section is
retried. When we retry, _primary.valid() will be false. We need to
ensure now that _lower_bound is always valid.
Fixes#2944.
