Articles Tagged: ORACLE RAC

Contention-Related Wait Events : It is common to see the gc cr block busy and gc current block busy wait events in Oracle RAC systems. These events occur when a consistent read or current block is needed from another instance yet it is taking some time to receive that block, and the sending of the […]

Load-oriented oracle RAC wait events : The load-oriented wait events indicate that a delay in processing has occurred in the GCS, which is usually caused by high load, CPU saturation and would have to be solved by additional CPUs, load-balancing, off loading processing to different times or a new cluster node. For the events mentioned, […]

Message-Oriented Oracle RAC wait event The message-oriented wait event statistics indicate that no block was received because it was not cached in any instance. Instead, a global grant was given, enabling the requesting instance to read the block from disk or modify it. If the local instance is the resource master, the grant happens immediately.If […]

To determine the amount of work and cost related to inter-instance messaging and contention, examine block transfer rates, remote requests made by each transaction, the number and time waited for global cache events as described under The response time for cache fusion transfers is determined by the messaging and processing times imposed by the physical […]

An event can be anything that Oracle has to perform on behalf of a set of instructions sent by the user interface. The term “wait” is used because every time a user connects to your application, a resource is allocated to perform tasks on its behalf. The waiting comes when a session is waiting for […]

The block-related wait event statistics indicate that a block was received as either the result of a 2-way or a 3-way message, that is, the block was sent from either the resource master requiring 1 message and 1 transfer, or was forwarded to a third node from which it was sent, requiring 2 messages and […]