Hi, We are currently using apache cassandra 3.11.6 in our production environment with single DC of 4 nodes.
2 nodes have configuration : Ssd 24 cores, 64gb ram, 20gb heap size Other 2 nodes have: Ssd 32cores, 64gb ram, 20gb heap size I have several questions around this. 1. Does different configuration nodes(cores) in single dc have any impact ? 2. Can we have different heap size in single DC on different nodes? 3. Which is better : single partition disk or multiple partition disk? 4. Currently we have 200 writes and around 5000 reads per sec per node (In 4 node cluster). How to determine max node capacity? 5. We are getting read/write operation timeout intermittently. There is no GC issue. However we have observed 1% packet loss between nodes. Can this be the cause of timeout issue? 6. Currently we are getting 1100 established connections from client side. Shall we increase native_transport_max_threads to 1000+? Currently we have increased it from default 128 to 512 after finding pending NTR requests during timeout issue. 7. Have found below h/w production recommendation from dse site. How much this is helpful for apache cassandra ? net.ipv4.tcp_keepalive_time=60 net.ipv4.tcp_keepalive_probes=3 net.ipv4.tcp_keepalive_intvl=10 net.core.rmem_max=16777216 net.core.wmem_max=16777216 net.core.rmem_default=16777216 net.core.wmem_default=16777216 net.core.optmem_max=40960 net.ipv4.tcp_rmem=4096 87380 16777216 net.ipv4.tcp_wmem=4096 65536 16777216
