GoldenGate學習筆記(10)_RAC環境

GoldenGate parameters settings for RAC

 

RAC Consideration:

1 All nodes in the RAC cluster must have synchronized system clocks. See also the MAXCOMMITPROPAGATIONDELAY option of the THREADOPTIONS parameter in the GoldenGate for Windows and UNIX Reference Guide.

(所有的節點的系統時鐘必須同步)

 

2 All nodes in the cluster must have the same COMPATIBLE parameter setting.

(所有的節點必須設定相同的相容版本)

 

3 To install GoldenGate in an Oracle Real Application Cluster (RAC) environment, install GoldenGate on the shared drive(s) that are accessed by the RAC nodes.

(GoldenGate binary file 應該安裝在所有節點都可訪問的共享檔案系統或共享磁碟上, 再將其掛載到RAC的其中一個節點.)

 

４If the archived logs reside in a location other than the Oracle default, specify that location

With the ALTARCHIVELOGDEST option of the TRANLOGOPTIONS parameter in the Extract parameter file.

(如果歸檔不是在預設路徑，則必須用TRANLOGOPTIONS引數的ALTARCHIVELOGDEST選項來指定)

You might also need to use the ALTARCHIVEDLOGFORMAT option of TRANLOGOPTIONS if the format that is specified with the Oracle parameter LOG_ARCHIVE_FORMAT contains sub-directories.

(同樣，如果歸檔格式不是採用的預設格式，也必須用TRANLOGOPTIONS引數的ALTARCHIVEDLOGFORMAT選項來指定)

 

5 After installing GoldenGate, configure the GoldenGate Manager process within the cluster application, as directed by the cluster documentation, so that GoldenGate will fail over properly with the other applications.

(在叢集應用下配置GoldenGate　？？？不理解 當RAC發生failover後，要重新調整GoldenGate抽取程式的抽取點。先不做)

 

6 Mounting logs that are stored on other platforms

If the online and archived redo logs are stored on a different platform. from the one the installed Extract is built for, do the following:

● NFS-mount the archive files.

● Map the file structure to the source Extract system’s Windows or UNIX file structure by using the LOGSOURCE and PATHMAP options of the Extract parameter TRANLOGOPTIONS.

See the reference documentation of this parameter for currently supported LOGSOURCE platforms.

NOTE If used, put the TRANLOGOPTIONS statement on one line. Do not use ampersand

(&) line terminators to split it into multiple lines.

 

7 Making logs available in a RAC configuration

In a RAC configuration, Extract must have access to the online and archived logs for all

nodes in the cluster, including the one where GoldenGate is installed.

(歸檔與online redo log 的可見性問題)

 

8 GoldenGate queues data in memory before sending it to the target system. The INQUEUESIZE and OUTQUEUESIZE options of the THREADOPTIONS parameter determine how much data to queue. If needed, you can increase the performance of Extract on Oracle RAC by tuning these parameters.

(效能調優問題)

 

9 Special procedures on RAC

 

9.1. If the primary database instance against which GoldenGate is running stops or fails

for any reason, Extract will abend. To resume processing, you can restart the instance,

or you can mount the GoldenGate binaries to another node where the database is

running and then restart the GoldenGate processes. Stop the Manager process on the

original node before starting GoldenGate processes from another node.(failover後的切換問題)

 

9.2. Any time the number of redo threads changes, the Extract group must be dropped and

re-created. For the recommended procedure, see Chapter 20 of the GoldenGate for

Windows and UNIX Administrator Guide(當Redo有更改後，重建抽取程式).

 

9.3. To write SQL operations to the trail, Extract must make sure that there are no other

operations from other RAC nodes that precede those in the current redo log that it is

reading. For example, if a log contains operations that were performed from 1:00 a.m.

to 2:00 a.m., and the log from Node 2 contains operations that were performed from

1:30 a.m. to 2:30 a.m., then only those operations up to, and including, the 2:00 a.m.

one can be moved to the server where the main Extract is coordinating the redo data.

Extract must ensure that there are no more operations between 2:00 a.m. and 2:30 a.m.

that need to be captured.

In active-passive environments, that requirement means that you might need to

perform. some operations and archive log switching on the passive node, to ensure that

operations from the active node are passed to the passive node. This eliminates any

issues that could arise from a slow archiver process, failed network links, and other

latency issues caused by moving archive logs from the Oracle nodes to the server where

the main Extract is coordinating the redo data.

 

9.4. To process the last transaction in a RAC cluster before shutting down Extract, insert a

dummy record into a source table that GoldenGate is replicating, and then switch log

files on all nodes. This will update the Extract checkpoint and confirm to the process

that all available archive logs are available to read. It also confirms that all

transactions in those archive logs are captured and written to the trail in the correct

order.(關閉RAC之前的善後工作)