Linux : SAR shows memory is increasing continously

Question

Only one application is running on the machine . When I run endurance test with high concurrency for 8 hours , SAR report shows memory usage increasing gradually . But application heap pattern remains constant and the application uses the memory well within the expected range . But system memory keeps on increasing throughout the time . I can't see any other process using high amount of memory ( using top command ) .

Answer 1

Most likely you are confusing memory usage and memory usage ...

As every UNIXy kernel, Linux is expected to use nearly all of the available memory over time: As a disk cache. This does of course not mean, that this portion of memory is lost for other uses - on demand these caches will be dropped to make room for applications etc.

The tool free (most likely used as free -m) will show you not only the free, but also the available memory. You will see, that while the free memory gets less and less over time, the available memory stays roughly the same (unless you actively use it).