Error: Failed to send data by channels - post mess

Question

I used LR for performance testing and encountered the below error:

Error: Failed to send data by channels - post message failed.

Does such error indicate agents number bottleneck? If so, I just need to add agents, right?

Thanks for the tips.

Answer 1

The error occurs on the Load Generator machine(s) when one of the threads under lr_bridge.exe that updates the eve files is not getting enough CPU time slice to be able to send events to the Controller. Enabling an additional flag in the mdrv.dat file on the LG machine will maintain the read and write threads for the eve files on the same main thread, thus allowing it to have all the CPU time needed.

To fix this issue :

Disable Web Diagnostics for J2EE/.NET. If the behavior remains, go through the next steps.

On all of the Load Generator machines where the Vusers are being executed, edit the \dat\mdrv.dat file by adding the line listed below in bold:

[lr_trans_server]

ExtPriorityType=transaction_server

WINNT_EXT_LIBS=trans_server.dll

WIN95_EXT_LIBS=trans_server.dll

LINUX_EXT_LIBS=libtrans_server.so

SOLARIS_EXT_LIBS=libtrans_server.so

HPUX_EXT_LIBS=libtrans_server.sl

AIX_EXT_LIBS=libtrans_server.so

LibCfgFunc=TransactionServer_configure

GetLoaderInterfaceFunc=get_ts_interface

AddLoaderClientInterfaceFunc=add_ts_client_interface

GetLoaderCommandLine=trans_server_extra_ext

Loader=1

ExtMessageQueue=0

SecurityMode=On

ExtCmdLineOverwrite=-eve_thread_run_on_main_thread

Save the changes in the mdrv.dat file then re-run the load test.