问题
Every 15 min I see this log entry:
2018-07-30 10:29:57,529 INFO [pool-1-thread-2] NoSpamLogger.java:91 log Maximum memory usage reached (512.000MiB), cannot allocate chunk of 1.000MiB
I´ve been reading through this Question, but I cant see anything wrong with my tables: NoSpamLogger.java Maximum memory usage reached Cassandra
I have 4 large tables:
iot_data/derived_device_data histograms
Percentile SSTables Write Latency Read Latency Partition Size Cell Count
(micros) (micros) (bytes)
50% 0.00 0.00 0.00 642 12
75% 0.00 0.00 0.00 17084 642
95% 0.00 0.00 0.00 263210 11864
98% 0.00 0.00 0.00 1629722 61214
99% 0.00 0.00 0.00 1955666 88148
Min 0.00 0.00 0.00 150 0
Max 0.00 0.00 0.00 4055269 152321
iot_data/derived_device_data_by_year histograms
Percentile SSTables Write Latency Read Latency Partition Size Cell Count
(micros) (micros) (bytes)
50% 0.00 0.00 0.00 51012 1597
75% 0.00 0.00 0.00 2346799 61214
95% 0.00 0.00 0.00 52066354 1629722
98% 0.00 0.00 0.00 52066354 1629722
99% 0.00 0.00 0.00 52066354 1629722
Min 0.00 0.00 0.00 6867 216
Max 0.00 0.00 0.00 52066354 1629722
iot_data/device_data histograms
Percentile SSTables Write Latency Read Latency Partition Size Cell Count
(micros) (micros) (bytes)
50% 0.00 29.52 0.00 2299 149
75% 0.00 42.51 0.00 182785 9887
95% 0.00 61.21 0.00 2816159 152321
98% 0.00 61.21 0.00 4055269 219342
99% 0.00 61.21 0.00 17436917 1131752
Min 0.00 17.09 0.00 43 0
Max 0.00 61.21 0.00 74975550 4866323
iot_data/device_data_by_week_sensor histograms
Percentile SSTables Write Latency Read Latency Partition Size Cell Count
(micros) (micros) (bytes)
50% 0.00 35.43 0.00 8239 446
75% 0.00 51.01 0.00 152321 8239
95% 0.00 61.21 0.00 2816159 152321
98% 0.00 61.21 0.00 4055269 219342
99% 0.00 61.21 0.00 12108970 785939
Min 0.00 20.50 0.00 43 0
Max 0.00 61.21 0.00 74975550 4866323
Altough I know that the derived_device_data // derived_device_data_by_year tables need some refactoring, none of them is close to the 100MB mark. Why am I getting this log entry though?
EDIT: I noticed the same log entry on my test systems, which are running almost without data but with the same configuration as prod. 12GB RAM, cassandra 3.11.2
回答1:
You may need to check the value of vm.max_map_count and and settings for swap. If swap is enabled, then it could affect performance of the both systems. Default value of vm.max_map_count could be also too low, and affect both Cassandra and Elasticsearch (see recommendation for ES).
Also, you may need explicitly set heap size for Cassandra and file_cache_size_in_mb - with 12Gb RAM, Cassandra will use 1/4 that is 3Gb, and file_cache_size_in_mb will be ~750Mb (1/4 of heap) - that could be too low.
P.S. Because it's logged as INFO, then it's considered harmless. See https://issues.apache.org/jira/browse/CASSANDRA-12221 & https://issues.apache.org/jira/browse/CASSANDRA-11681
回答2:
Not sure about this specific problem, but maybe try checking the jvm.options file in your Cassandra's config dir. You might want to increase the Xmx or other settings.
来源：https://stackoverflow.com/questions/51591253/cassandra-nospamlogger-log-maximum-memory-usage-reached