I have 4 nodes on enterprise type hardware (Lots of Ram 12GB, 16 i7 cores, RAID Disks).
~# /opt/cassandra/bin/nodetool --host=localhost --port=8181 tpstats Pool Name Active Pending Completed STREAM-STAGE 0 0 0 RESPONSE-STAGE 0 0 516280 ROW-READ-STAGE 8 4096 1164326 LB-OPERATIONS 0 0 0 *MESSAGE-DESERIALIZER-POOL 1 682008 1818682* GMFD 0 0 6467 LB-TARGET 0 0 0 CONSISTENCY-MANAGER 0 0 661477 ROW-MUTATION-STAGE 0 0 998780 MESSAGE-STREAMING-POOL 0 0 0 LOAD-BALANCER-STAGE 0 0 0 FLUSH-SORTER-POOL 0 0 0 MEMTABLE-POST-FLUSHER 0 0 4 FLUSH-WRITER-POOL 0 0 4 AE-SERVICE-STAGE 0 0 0 HINTED-HANDOFF-POOL 0 0 3 EQX r...@cass04:~# vmstat -n 1 procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------ r b swpd free buff cache si so bi bo in cs us sy id wa st 6 10 7096 121816 16244 10375492 0 0 1 3 0 0 5 1 94 0 0 2 10 7096 116484 16248 10381144 0 0 5636 4 21210 9820 2 1 79 18 0 1 9 7096 108920 16248 10387592 0 0 6216 0 21439 9878 2 1 81 16 0 0 9 7096 129108 16248 10364852 0 0 6024 0 23280 8753 2 1 80 17 0 2 9 7096 122460 16248 10370908 0 0 6072 0 20835 9461 2 1 83 14 0 2 8 7096 115740 16260 10375752 0 0 5168 292 21049 9511 3 1 77 20 0 1 10 7096 108424 16260 10382300 0 0 6244 0 21483 8981 2 1 75 22 0 3 8 7096 125028 16260 10364104 0 0 5584 0 21238 9436 2 1 81 16 0 3 9 7096 117928 16260 10370064 0 0 5988 0 21505 10225 2 1 77 19 0 1 8 7096 109544 16260 10376640 0 0 6340 28 20840 8602 2 1 80 18 0 0 9 7096 127028 16240 10357652 0 0 5984 0 20853 9158 2 1 79 18 0 9 0 7096 121472 16240 10363492 0 0 5716 0 20520 8489 1 1 82 16 0 3 9 7096 112668 16240 10369872 0 0 6404 0 21314 9459 2 1 84 13 0 1 9 7096 127300 16236 10353440 0 0 5684 0 38914 10068 2 1 76 21 0 *But the 16 cores are hardly utilized. Which indicates to me there is some bad thread thrashing, but why? * 1 [||||| 8.3%] Tasks: 1070 total, 1 running 2 [ 0.0%] Load average: 8.34 9.05 8.82 3 [ 0.0%] Uptime: 192 days(!), 15:29:52 4 [||||||||||| 17.9%] 5 [||||| 5.7%] 6 [|| 1.3%] 7 [|| 2.6%] 8 [| 0.6%] 9 [| 0.6%] 10 [|| 1.9%] 11 [|| 1.9%] 12 [|| 1.9%] 13 [|| 1.3%] 14 [| 0.6%] 15 [|| 1.3%] 16 [| 0.6%] Mem[||||||||||||||||||||||||||||||||||||||||||||1791/12028MB] Swp[| 6/1983MB] PID USER PRI NI VIRT RES SHR S CPU% MEM% TIME+ Command 30269 root 40 0 14100 2116 900 R 4.0 0.0 0:00.49 htop 24878 root 40 0 20.6G 8345M 6883M D 3.0 69.4 1:23.03 /opt/java/bin/java -ea -Xms1G -Xmx7G -XX:+UseParNewGC -XX:+UseConcMark 24879 root 40 0 20.6G 8345M 6883M D 3.0 69.4 1:22.93 /opt/java/bin/java -ea -Xms1G -Xmx7G -XX:+UseParNewGC -XX:+UseConcMark 24874 root 40 0 20.6G 8345M 6883M D 2.0 69.4 1:22.73 /opt/java/bin/java -ea -Xms1G -Xmx7G -XX:+UseParNewGC -XX:+UseConcMark 24880 root 40 0 20.6G 8345M 6883M D 2.0 69.4 1:22.93 /opt/java/bin/java -ea -Xms1G -Xmx7G -XX:+UseParNewGC -XX:+UseConcMark 24875 root 40 0 20.6G 8345M 6883M D 2.0 69.4 1:23.17 /opt/java/bin/java -ea -Xms1G -Xmx7G -XX:+UseParNewGC -XX:+UseConcMark 24658 root 40 0 20.6G 8345M 6883M D 2.0 69.4 1:23.06 /opt/java/bin/java -ea -Xms1G -Xmx7G -XX:+UseParNewGC -XX:+UseConcMark 24877 root 40 0 20.6G 8345M 6883M S 2.0 69.4 1:23.43 /opt/java/bin/java -ea -Xms1G -Xmx7G -XX:+UseParNewGC -XX:+UseConcMark 24873 root 40 0 20.6G 8345M 6883M D 1.0 69.4 1:23.65 /opt/java/bin/java -ea -Xms1G -Xmx7G -XX:+UseParNewGC -XX:+UseConcMark 24876 root 40 0 20.6G 8345M 6883M S 1.0 69.4 1:23.62 /opt/java/bin/java -ea -Xms1G -Xmx7G -XX:+UseParNewGC -XX:+UseConcMark 24942 root 40 0 20.6G 8345M 6883M S 1.0 69.4 0:23.50 /opt/java/bin/java -ea -Xms1G -Xmx7G -XX:+UseParNewGC -XX:+UseConcMark 24943 root 40 0 20.6G 8345M 6883M S 0.0 69.4 0:29.53 /opt/java/bin/java -ea -Xms1G -Xmx7G -XX:+UseParNewGC -XX:+UseConcMark 24933 root 40 0 20.6G 8345M 6883M S 0.0 69.4 0:22.57 /opt/java/bin/java -ea -Xms1G -Xmx7G -XX:+UseParNewGC -XX:+UseConcMark 24939 root 40 0 20.6G 8345M 6883M S 0.0 69.4 0:12.73 /opt/java/bin/java -ea -Xms1G -Xmx7G -XX:+UseParNewGC -XX:+UseConcMark 25280 root 40 0 20.6G 8345M 6883M S 0.0 69.4 0:00.10 /opt/java/bin/java -ea -Xms1G -Xmx7G -XX:+UseParNewGC -XX:+UseConcMark