Troubleshooting sqlplus logon instance slow and Swap usage high even memory is 50% free
A few days ago, I encountered a case, a 11.2.0.4 three-node Oracle RAC database on RHEL 6.6 , when trying to login to the database instance using sqlplus “/ as sysdba” on the third node, It’s very slow, and vmstat show that there is a very large swap in and out, but there is still a lot of memory free space
Troubleshooting Out-Of-Memory(OOM) killer db crash when memory exhausted
If kernel can not find memory to allocate when it’s needed, it puts in-use user data pages on the swap-out queue, to be swapped out. If the Virtual Memory (VM) cannot allocate memory and canot swap out in-use memory, the Out-of-memory killer may begin killing current userspace processes.
Oracle12c R2注意事项： Active DataGuard logon fail with ORA-00604& ORA-04024
一套12c R2 4-nodes Oracle RAC on RHEL 7的环境，已安装0417 RU。 该库有一套Phyical DataGard， 同时也是GoldenGate的target端，存在一个replicat 进程同步数据，因为OGG的认证导致ADG hang最终使归档删除失败。
