Usage of ByteBuffer breaks the application with Oracle 17

[masesdevelopers]

Seems that the exception is raised when it is enabled the usage of *Buffer classes (ByteBuffer, IntBuffer, end so on) even increasing the Heap memory allocated at application startup.

Originally posted by @masesdevelopers in #1140

[masesdevelopers]

Execute tests on branch release/2.5.X and try older version like 2.6.0, 2.6.1 or 2.6.2

[masesdevelopers]

Execute tests on branch release/2.5.X and try older version like 2.6.0, 2.6.1 or 2.6.2

Executing tests with:

• 2.5.X (Aligned version 2.5.X to latest updates of master #725): no issues are raised
• 2.6.2: no issues are raised

However another issue, that was trapped with #704, is not evident in the tests executed with 2.5.X and 2.6.2, but it is reported in all tests of #723:

TestInsertByteBuffers with 100 iterations and 100000000 length
Created TestArrayAndByteBuffer
Break insertArray at iteration 42 due to Java.Lang.OutOfMemoryError: Java heap space

The specific test was executing an array transfer of 100MBytes and it was trying to iterate over 100 executions: all tests stops at the same point: 42th iteration. Seems that GC was not able to recover the memory consumed on each iteration:

• considering that each iteration consumes 100MBytes
• multiplying for 42
• the final memory requested is 4.2 GBytes which is over the maximum heap size defined from the test

A possible verification of the above hypothesis is to change the value of ApplicationHeapSize from 4G to 6G to verify if the application stops later.
Then an issue shall be opened since, between JCOBridge 2.6.2 and 2.6.3, the tests does not work as expected.

[masesdevelopers]

However another issue, that was trapped with #704, is not evident in the tests executed with 2.5.X and 2.6.2, but it is reported in all tests of #723:

TestInsertByteBuffers with 100 iterations and 100000000 length
Created TestArrayAndByteBuffer
Break insertArray at iteration 42 due to Java.Lang.OutOfMemoryError: Java heap space

The specific test was executing an array transfer of 100MBytes and it was trying to iterate over 100 executions: all tests stops at the same point: 42th iteration. Seems that GC was not able to recover the memory consumed on each iteration:

* considering that each iteration consumes 100MBytes

* multiplying for 42

* the final memory requested is 4.2 GBytes which is over the maximum heap size defined from the test

A possible verification of the above hypothesis is to change the value of ApplicationHeapSize from 4G to 6G to verify if the application stops later. Then an issue shall be opened since, between JCOBridge 2.6.2 and 2.6.3, the tests does not work as expected.

Executing tests with a maximum heap size of 6G lead to this:

TestInsertByteBuffers with 100 iterations and 100000000 length
Created TestArrayAndByteBuffer
Break insertArray at iteration 63 due to Java.Lang.OutOfMemoryError: Java heap space

the correlation between maximum heap size and OutOfMemoryError is clear.

[masesdevelopers]

Closed by #717 (comment)