RAM requirements
When configuring instances of CDC Replication, the default values are used for memory allocation.
When configuring instances of CDC Replication, the defaults for memory allocation are as follows:
| Product | Required RAM |
|---|---|
| Each instance of CDC Replication | 1024 MB |
| CDC Replication Engine for Db2® for i | 512 MB of available pooled memory |
| Access Server | 512 MB (1024 MB is recommended) |
| Management Console | 512 MB (1024 MB is recommended) |
| IBM® Classic CDC for z/OS® Classic Data Architect | 1 GB |
Although CDC Replication memory requirements will fluctuate, you must work with your system administrator to ensure the allocated memory for each instance of the product is available at all times. This may involve deployment planning since other applications with memory requirements may be installed on the same server with CDC Replication. Using values other than the defaults or allocating more RAM than is physically available on your server should only be undertaken after considering the impacts on product performance.
- A possible performance degradation as the operating system on your server increasingly relies on virtual memory and disk I/O.
- Additional CPU resources may be consumed as the product spends more time cleaning up memory.
- Restricted throughput. Replication may be slow or pause due to an increased reliance on virtual memory and disk I/O.
- Replication may be slow as the product processes smaller units of work to preserve memory.
- Disk-staging of transactions by the CDC Replication source deployment.
- Out-of-memory exceptions, time outs, monitoring issues, and configuration issues with command line tools or Management Console.
For information on storage requirements for CDC Replication Engine for Db2 for z/OS, see Storage above the bar