Hi, We are testing Cassandra here, we would like to use it to store some data : - about 1000 inserts / seconds in a CF "RAW" : Column : TimeUUID (timeuuid of the insert, so 1000 new columns / second) Row : YYYYMMDDHH of the insert (to minimize the size of rows, the biggest one is 2GB data), for example for today at 1:30pm, the row of an insert will be 2010070713 - 4 CF we are using for indexes, all have the same structure Column : TimeUUID of the insert (about 300 new columns per second, each correspond to the same timeuuid of the CF "RAW". Row : a String (Customer Id).
The goal is for a Customer, to be able to get all its "RAW" for a time range. Currently Cassandra is running on 4 nodes / 16 GB RAM each, 8 GB JVM_MAX_MEM It runs correctly during several days. Last night, we started to have timeout exception on insert and high cpu load on all nodes. We stopped inserts. But the CPU remains high (without any insert or read). We tried to stop and start nodes again, cpu remains high (between 100% and 150%). So currently, we can't add more data (timeout exceptions, due to high cpu usage I guess). Could you help me to understand what's wrong ? :) Cheers, Olivier Here are some data : We are using Cassandra 0.6.2 Address Status Load Range Ring 170141183460469231731687303715884105728 192.168.0.1 Up 23.43 GB 42535295865117307932921825928971026432 |<--| 192.168.0.2 Up 23.12 GB 85070591730234615865843651857942052864 | | 192.168.0.3 Up 24.47 GB 127605887595351923798765477786913079296 | | 192.168.0.4 Up 24.14 GB 170141183460469231731687303715884105728 |-->| Keyspace: system Read Count: 8 Read Latency: 60.38625 ms. Write Count: 13 Write Latency: 0.3583076923076923 ms. Pending Tasks: 0 Column Family: HintsColumnFamily SSTable count: 1 Space used (live): 103812 Space used (total): 103812 Memtable Columns Count: 0 Memtable Data Size: 0 Memtable Switch Count: 0 Read Count: 5 Read Latency: 83,440 ms. Write Count: 0 Write Latency: NaN ms. Pending Tasks: 0 Key cache capacity: 1 Key cache size: 1 Key cache hit rate: 0.6666666666666666 Row cache: disabled Compacted row minimum size: 0 Compacted row maximum size: 0 Compacted row mean size: 0 Column Family: LocationInfo SSTable count: 3 Space used (live): 3999 Space used (total): 3999 Memtable Columns Count: 7 Memtable Data Size: 227 Memtable Switch Count: 2 Read Count: 3 Read Latency: 21,964 ms. Write Count: 13 Write Latency: 0,358 ms. Pending Tasks: 0 Key cache capacity: 3 Key cache size: 3 Key cache hit rate: 0.2 Row cache: disabled Compacted row minimum size: 0 Compacted row maximum size: 0 Compacted row mean size: 0 ---------------- Keyspace: MyKeySpace Read Count: 5 Read Latency: 22737.799 ms. Write Count: 0 Write Latency: NaN ms. Pending Tasks: 0 Column Family: INDEX1 SSTable count: 5 Space used (live): 1502023165 Space used (total): 1502023165 Memtable Columns Count: 0 Memtable Data Size: 0 Memtable Switch Count: 0 Read Count: 1 Read Latency: 0,876 ms. Write Count: 0 Write Latency: NaN ms. Pending Tasks: 0 Key cache capacity: 200000 Key cache size: 0 Key cache hit rate: NaN Row cache: disabled Compacted row minimum size: 0 Compacted row maximum size: 0 Compacted row mean size: 0 Column Family: INDEX2 SSTable count: 3 Space used (live): 1262977087 Space used (total): 1262977087 Memtable Columns Count: 0 Memtable Data Size: 0 Memtable Switch Count: 0 Read Count: 1 Read Latency: 0,547 ms. Write Count: 0 Write Latency: NaN ms. Pending Tasks: 0 Key cache capacity: 200000 Key cache size: 0 Key cache hit rate: NaN Row cache: disabled Compacted row minimum size: 0 Compacted row maximum size: 0 Compacted row mean size: 0 Column Family: RAW SSTable count: 6 Space used (live): 18867913004 Space used (total): 18867913004 Memtable Columns Count: 0 Memtable Data Size: 0 Memtable Switch Count: 0 Read Count: 1 Read Latency: 113685,183 ms. Write Count: 0 Write Latency: NaN ms. Pending Tasks: 0 Key cache capacity: 200000 Key cache size: 3 Key cache hit rate: 0.0 Row cache: disabled Compacted row minimum size: 215734 Compacted row maximum size: 1055255881 Compacted row mean size: 491170239 Column Family: INDEX3 SSTable count: 6 Space used (live): 1667728231 Space used (total): 1667728231 Memtable Columns Count: 0 Memtable Data Size: 0 Memtable Switch Count: 0 Read Count: 1 Read Latency: 1,241 ms. Write Count: 0 Write Latency: NaN ms. Pending Tasks: 0 Key cache capacity: 200000 Key cache size: 0 Key cache hit rate: NaN Row cache: disabled Compacted row minimum size: 0 Compacted row maximum size: 0 Compacted row mean size: 0 Column Family: INDEX4 SSTable count: 7 Space used (live): 2620328669 Space used (total): 2620328669 Memtable Columns Count: 0 Memtable Data Size: 0 Memtable Switch Count: 0 Read Count: 1 Read Latency: 1,148 ms. Write Count: 0 Write Latency: NaN ms. Pending Tasks: 0 Key cache capacity: 200000 Key cache size: 0 Key cache hit rate: NaN Row cache: disabled Compacted row minimum size: 0 Compacted row maximum size: 0 Compacted row mean size: 0