Cassandra   @Appdata

geography


cluster setup


Node: AWS c3.2xlarge | 15 GB RAM, 8 Cores | 2x60GB SSD drives

CoreOS, Docker, fleet/etcd

Java HEAP = 8GB | Commit log dir & Data dir @ separate phisical disks

Keyspace: 
CREATE KEYSPACE packetdata WITH replication = {'class': 'NetworkTopologyStrategy', 'eu-west_analytics': 2, 'ap-southeast_cassandra' : 2};

PERFORMANCE benchmarks

[LIVE demo]


Results:
op rate                   : 5271
partition rate            : 5271
row rate                  : 134434
latency mean              : 51.3
latency median            : 20.2
latency 95th percentile   : 175.4
latency 99th percentile   : 231.5
latency 99.9th percentile : 255.1
latency max               : 2393.6
total gc count            : 907
total gc mb               : 601200
total gc time (s)         : 233
avg gc time(ms)           : 257
stdev gc time(ms)         : 1333
Total operation time      : 00:00:59
Improvement over 181 threadCount: 6%
Sleeping for 15s
Running with 406 threadCount
Running [insert] with 406 threads 1 minutes

probelms being solved


For our specific case of two regions (Europe and Asia) next parameters are appropriate and proved to be working:
- etcd `peer-heartbeat-interval: 1000`
- etcd `peer-election-timeout: 4000`
- fleet `etcd-request-timeout: 15`

[Cassandra timeout during write query at consistency ONE (1 replica were required but only 0 acknowledged the write)]
Check the output of `cassandra-stress` for the line like [Using data-center name 'eu-west_analytics' for DCAwareRoundRobinPolicy]
Use `-node whitelist 52.16.151.33,52.16.119.105,52.16.53.144` [CASSANDRA-8313]



CASCADING CLUSTER FAILURE on container restart: SSTables went out of sync ->
(re)Synchronization carousel
RESOLVED: using host FS for storing commit logs and 


Agents: until OpsCenter not created its specific keyspace agents fail to publish JMX data into it and OpsCenter fails to communicate with them.
RESOLVED: Ansible Agents Installation (demo)



broadcast_address | broadcast_rpc_address | listen_address | rpc_address
SST compaction overhead -> switch to using SSD drives (default: slow EBS)

next steps

  • Spark JobServer
  • Security (C* | Spark | etcd)
  • Cassandra CF tuning

CREATE TABLE packets (
owner uuid,
...
PRIMARY KEY ((owner, ...), ...)
) WITH
bloom_filter_fp_chance=0.100000 AND
caching='KEYS_ONLY' AND
comment='' AND
dclocal_read_repair_chance=0.000000 AND
gc_grace_seconds=864000 AND
index_interval=128 AND
read_repair_chance=0.100000 AND
replicate_on_write='true' AND
default_time_to_live=0 AND
speculative_retry='99.0PERCENTILE' AND
memtable_flush_period_in_ms=0 AND
compaction={'class': 'SizeTieredCompactionStrategy'} AND
compression={'sstable_compression': 'LZ4Compressor'};

Cassandra   @Appdata

By Anton Kirillov

Cassandra   @Appdata

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