Troubleshooting

karlarao's picture

Diagnosing and Resolving “gc block lost”

Last week, one of our clients had a sudden slow down on all of their applications which is running on two node RAC environment

Below is the summary of the setup:
– Server and Storage: SunFire X4200 with LUNs on EMC CX300
– OS: RHEL 4.3 ES
– Oracle 10.2.0.3 (database and clusterware)
– Database Files, Flash Recovery Area, OCR, and Voting disk are located on OCFS2 filesystems
– Application: Forms and Reports (6i and also lower)

As per the DBA, the workload on the database was normal and there were no changes on the RAC nodes and on the applications. Hmm, I can’t really tell because I haven’t really looked into their workload so I don’t have past data to compare.

karlarao's picture

OS Thread Startup

Recently I encountered a performance problem scenario where a simple sqlplus “/ as sysdba” took about 2minutes to finish, this is critical to the client’s business because they have a local C program that loads Call Detail Reports on the database making use of local authentication for most of its operations and Sql*Loader to load the data, so this “2minutes of waiting” when accumulated greatly consumes significant time on their operations and greatly impacts the business.

When I arrived on the client I first checked the alert logs of both ASM (they have a separate home for ASM) and RDBMS, there were no errors…

Then I checked on the server to see if there were any CPU, IO, memory, swap, and network bottlenecks going on

The CPU run queue was zero and most of the time 90% idle

The disks were also most of the time idle

The memory utilization was low with 430MB free

Syndicate content