Intermittent memory issues - codec.cpp:1135: std::bad_alloc

[Peiyun Shi via Tech-talk <tech-talk@aps.anl.gov>]

Dear Tech-talk list moderators,

I am Peiyun Shi, a staff research scientist from the FLARE facility in PPPL. We are using EPICS for our main control system. However, we encountered this intermittent memory issue as described below. Could you please help publish this to the maillist to seek for some help?

We used pvaccess python package to implement EPICS communication between one Windows main control PC and one National Instruments CompactRIO controller. This setup usually works as expected, but intermittently memory issues appear. Below is the sample error message:
_an exception caught while in receiveThread at ../../src/ remote/codec.cpp:1135: std::bad_alloc
Error on UDP RX 10.60.1.12:60023 -> 10.60.1.255:5076 at 91 : std::bad_alloc
0x00 ca020003 55000000 ba0b0000 00000000 .... U... .... ....
0x10 00000000 00000000 0000ffff 00000000 .... .... .... ....
0x20 77ea0103 74637002 00d34120 1015666c w... tcp. ..A ..fl
0x30 6172652e 6c6f672e 706f7374 5f726563 are. log. post rec
0x40 6f7264d4 41201015 666c6172 652e6c6f ord. A .. flar e.lo
0x50 672e706f 73745f72 65636f72 64 g.po st_r ecor d

It seems that pvaccess requests too large memory from the CompactRIO controller, which collapses it. Is this the case?
If so, how can we avoid this situation by ignoring large-memory-allocation requests?

Thanks,

Peiyun