Reading from remote logs setup of GoldenGate

Configure GoldenGate Extract to read from remote logs

Sometimes you may need to run GoldenGate on different machines than the ones that host the database. It is possible but there are restrictions that apply. First is that the endian order of both the systems should be same and the second is the bit-width has to be same. For example it is not possible to run GoldenGate on a 32-bit system to read from a database that runs on some 64-bit platform. Assuming that the environment satisfies the above two conditions; we can use the LOGSOURCE option of TRANSLOGOPTIONS to achieve this.

Here we run GG on host goldengate1 (192.168.0.109) and the database from which we want to capture the changes runs on the host goldengate3 (192.168.0.111) so two different hosts. Both the systems run 11.2.0.2 on RHEL 5.5. On goldengate3 redo logs are in the mount point /home which has been NFS mounted on goldengate1 as /home_gg3

This requires an NFS mount between systems for redo logs, not a goldengate process

Filesystem           1K-blocks      Used Available Use% Mounted on

192.168.0.111:/home   12184800   7962496   3593376  69% /home_gg3

The Extract parameters are as follows:

EXTRACT ERMT01

USERID ggadmin@orcl3, PASSWORD ggadmin

EXTTRAIL ./dirdat/er

TRANLOGOPTIONS LOGSOURCE LINUX, PATHMAP /home/oracle/app/oracle/oradata/orcl /home_gg3/oracle/app/oracle/oradata/or
cl, PATHMAP /home/oracle/app/oracle/flash_recovery_area/ORCL/archivelog /home_gg3/oracle/app/oracle/flash_recovery_
area/ORCL/archivelog

TABLE HR.*;

(The text in the line starting with TRANLOGOPTIONS is a single line)

So using PATHMAP we can make GG aware about the actual location of the redo logs & archive logs on the remote server and the mapped location on the system where GG is running (It is somewhat like db_file_name_convert option for Data Guards).

We fire some DMLs on the source database and then run stats command for the Extract

GGSCI (goldengate1) 93> stats ermt01 totalsonly *

Sending STATS request to EXTRACT ERMT01 ...

Start of Statistics at 2012-05-26 05:17:05.

Output to ./dirdat/er:

Cumulative totals for specified table(s):

*** Total statistics since 2012-05-26 04:51:10 ***
        Total inserts                                1.00
        Total updates                                0.00
        Total deletes                                1.00
        Total discards                               0.00
        Total operations                             2.00
.
.
.

End of Statistics.

GGSCI (goldengate1) 94>

For more details have a look at the GG reference guide (Page 402).

 

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