"This patchset allows Scylla to determine the size of a memtable instead
of relying in the user-provided memtable_cleanup_threshold. It does that
by allowing the region_group to specify a soft limit which will trigger
the allocation as early as it is reached.
Given that, we'll keep the memtables in memory for as long as it takes
to reach that limit, regardless of the individual size of any single one
of them. That limit is set to 1/4 of dirty memory. That's the same as
last submission, except this time I have run some experiments to gauge
behavior of that versus 1/2 of dirty memory, which was a preferred
theoretical value.
After that is done, the flush logic is reworked to guarantee that
flushes are not initiated if we already have one memtable under flush.
That allow us to better take advantage of coalescing opportunities with
new requests and prevents the pending memtable explosion that is
ultimately responsible for Issue 1817.
I have run mainly two workloads with this. The first one a local RF=1
workload with large partitions, sized 128kB and 100 threads. The results
are:
Before:
op rate : 632 [WRITE:632]
partition rate : 632 [WRITE:632]
row rate : 632 [WRITE:632]
latency mean : 157.8 [WRITE:157.8]
latency median : 115.5 [WRITE:115.5]
latency 95th percentile : 486.7 [WRITE:486.7]
latency 99th percentile : 534.8 [WRITE:534.8]
latency 99.9th percentile : 599.0 [WRITE:599.0]
latency max : 722.6 [WRITE:722.6]
Total partitions : 189667 [WRITE:189667]
Total errors : 0 [WRITE:0]
total gc count : 0
total gc mb : 0
total gc time (s) : 0
avg gc time(ms) : NaN
stdev gc time(ms) : 0
Total operation time : 00:05:00
END
After:
op rate : 951 [WRITE:951]
partition rate : 951 [WRITE:951]
row rate : 951 [WRITE:951]
latency mean : 104.8 [WRITE:104.8]
latency median : 102.5 [WRITE:102.5]
latency 95th percentile : 155.8 [WRITE:155.8]
latency 99th percentile : 177.8 [WRITE:177.8]
latency 99.9th percentile : 686.4 [WRITE:686.4]
latency max : 1081.4 [WRITE:1081.4]
Total partitions : 285324 [WRITE:285324]
Total errors : 0 [WRITE:0]
total gc count : 0
total gc mb : 0
total gc time (s) : 0
avg gc time(ms) : NaN
stdev gc time(ms) : 0
Total operation time : 00:05:00
END
The other workload was the workload described in #1817. And the result
is that we now have a load that is very stable around 100k ops/s and
hardly any timeouts, instead of the 1.4 baseline of wild variations
around 100k ops/s and lots of timeouts, or the deep reduction of
1.5-rc1."
* 'issue-1817-v4' of github.com:glommer/scylla:
database: rework memtable flush logic
get rid of max_memtable_size
pass a region to dirty_memory_manager accounting API
memtable: add a method to expose the region_group
logalloc: allow region group reclaimer to specify a soft limit
database: remove outdated comment
database: uphold virtual dirty for system tables.
(cherry picked from commit 5d067eebf2)
Files with a conf extension are run by the scylla_prepare on the AMI.
The scylla-housekeeping configuration file is not a bash script and
should not be run.
This patch changes its extension to cfg which is more python like.
Signed-off-by: Amnon Heiman <amnon@scylladb.com>
Message-Id: <1470896759-22651-2-git-send-email-amnon@scylladb.com>
The housekeeping.conf is a configuration file for scylla-housekeeping.
By default it will be included in the rpm and state that the
check-version would be run.
If the file is missing, or if check-version is set to false, the check
version operation will not be performed.
Signed-off-by: Amnon Heiman <amnon@scylladb.com>
This patch adds the prometheus API it adds the proto library to the
compilation, adds an optional configuration parameter to change the
prometheus listening port and start the prometheus API in main.
To disable the prometheus API, set its listening port to 0.
Signed-off-by: Amnon Heiman <amnon@scylladb.com>
Message-Id: <1470231628-22831-2-git-send-email-amnon@scylladb.com>
Fixes#614
* Use warning threshold from config
* Don't throw exceptions. We're only supposed to warn.
* Try to actually estimate mutation data payload size, not
number of mutations.
Describe scylla version of option.
Note, for test usage, the below should be workable:
server_encryption_options:
internode_encryption: all
certificate: seastar/tests/test.crt
truststore: seastar/tests/catest.pem
keyfile: seastar/tests/test.key
Since the seastar test suite contains a snakeoil cert + trust
combo
This patch substitutes uint64_t for uint32_t as the type for
commitlog_total_space_in_mb. Moving to 64 is not strictly needed, since even a
signed 32-bit type would allow us to easily handle 2TB. But since we store that
in the commitlog as a 64-bit value, let's match it.
Moving from unsigned to signed, however, allow us to represent negative
numbers. With that in place, we can change the semantics of the value
slightly, so to allow a negative number to mean "all memory".
The reason behind this, is that the default value "8GB", is an artifact of the
JVM. We don't need that, and in many-shards configuration, each shard flushes
the commitlog way too often, since 8GB / many_shards = small_number.
8GB also happens to be a popular heap size for C* in the JVM. For us, we would
like to equate that (at least) with the amount of memory. The problem is how to
do that without introducing new options or changing the semantics of existing
options too radically.
The proposed solution will allow us to still parse C* yaml files, since those
will always have positive numbers, while introducing our own defaults.
Signed-off-by: Glauber Costa <glommer@scylladb.com>
This is a configuration file used by GossipingPropertyFileSnitch and
EC2SnitchXXX snitches family.
Signed-off-by: Vlad Zolotarov <vladz@cloudius-systems.com>
This patch rearrange scylla.yaml, without adding or omitting parameters, to two segments:
1. Supported parameters
2. Not supported parameters: saved for future use or backward compatibility
Signed-off-by: Tzach Livyatan <tzach@cloudius-systems.com>
The are additional items that need to be updated and aligned:
token-vnodes, snitches, save_cached etc.
Signed-off-by: Shlomi Livne <shlomi@cloudius-systems.com>
