财神爷

書名： INSTANT Oracle GoldenGate
作者名： Tony Bruzzese
本章字數： 586字
更新時間： 2021-08-13 16:47:08

How to do it…

In order to support your GoldenGate installation, you must ensure you have ample physical memory (RAM) available on the server. The steps for implementing the design considerations are as follows:

The following command will display your available memory on the server:
```
$ /usr/sbin/lsattr –El sys0 –a realmmem
```
The output of the preceding command will be as follows:
```
Realmem 16777216 Amount of usable physical memory in Kbytes False
```
The preceding output indicates that the server has 16 GB of physical RAM, which is more than sufficient to carry on for an Online Transaction Processing (OLTP) environment.
For very busy systems, you can limit the amount of RAM to your Extract and/or Replicat processes as in the following parameter file:
```
cachemgr cachesize 8G
```
Your OGG software distribution should have its own filesystem created by your system administrator. Our example is a 100 GB filesystem.
```
hosta> $ df -g
```
The output of the preceding command will be as follows:
```
Filesystem GB blocks Free % Used Iused %Iused Mounted on
…
/dev/oggvg 100.00 99.67 1% 270 1% /u01/app/oracle/GG
```
Next we want to calculate the optimal network bandwidth in order to set the TCP Send / Receive socket buffers (TCPBUFSIZE) for data pump extracts. Use the following command to get the correct TCPBUFSIZE buffers for your data pump extract:
```
hosta> $ ping -c 10 hostb
```
The output of the preceding command will be as follows:
```
PING hostb: (10.3.4.5): 56 data bytes
64 bytes from 10.3.4.5: icmp_seq=0 ttl=255 time=0.8 ms
64 bytes from 10.3.4.5: icmp_seq=1 ttl=255 time=0.8 ms
64 bytes from 10.3.4.5: icmp_seq=2 ttl=255 time=0.8 ms
64 bytes from 10.3.4.5: icmp_seq=3 ttl=255 time=0.8 ms
64 bytes from 10.3.4.5: icmp_seq=4 ttl=255 time=0.8 ms
64 bytes from 10.3.4.5: icmp_seq=5 ttl=255 time=0.8 ms
64 bytes from 10.3.4.5: icmp_seq=6 ttl=255 time=0.8 ms
64 bytes from 10.3.4.5: icmp_seq=7 ttl=255 time=0.7 ms
64 bytes from 10.3.4.5: icmp_seq=8 ttl=255 time=0.8 ms
64 bytes from 10.3.4.5: icmp_seq=9 ttl=255 time=0.8 ms

----hostb PING Statistics----
10 packets transmitted, 10 packets received, 0% packet loss
round-trip min/avg/max = 0.8/0.8/0.8 ms
```
Now we'll calculate the buffer size based on the preceding output of 0.8 ms network latency and our 100 megabits interface card. You might have a different speed interface card such as 1 gigabit or even 10 gigabits. Check with your system administrator if you're unsure.

Note

0.8 seconds * 100 megabits per second = 8 megabits

To determine the buffer size in bytes, where 8 bits = 1 byte, we perform the following calculation:
8 megabits / 8 = 1,000,000 bytes ~ 1 MB / second = TCPBUFSIZE
Create an Oracle service for OGG to connect to the Oracle database via a service name in a high availability Real Application Clusters (RAC) database as follows:
```
$ srvctl add service -d sourcedb -s OGG_SRVC –r hosta1 –a hosta2
$ srvctl start service –d sourcedb –s OGG_SRVC
```

Once the OGG_SRVC service has been created from the preceding code, you must add it to your tnsnames.ora file, for example, as follows:

OGG_SRVC =
(DESCRIPTION =
   (ADDRESS = (PROTOCOL = TCP)(HOST = hosta1-vip)(PORT = 1521))
   (ADDRESS = (PROTOCOL = TCP)(HOST = hosta2-vip)(PORT = 1521))
   (LOAD_BALANCE = NO)
   (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = OGG_SRVC)
   )
)

For very slow networks, or networks with bandwidth limitations, you would benefit highly by enabling network compression in the data pump extract. We can do it using the following example:
Example: enabling compression for your trail files in flight as follows:
```
rmthost london mgrport 7809 tcpbufsize 1000000 compress
```

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INSTANT Oracle GoldenGate

How to do it…

Note