foundry27 : Post

Forum Topic - Qnet and CRC checking: (2 Items)

View: as

Mark Anderson

12/08/2010 5:06 PM

post77963

I have implemented a QNet client and server application where data is passes between the two using an mqueue.  I want 
the data to be checked for corruption using a CRC so I specified the do_crc=1 and enforce_crc=1 options.  How will I be 
notified, if at all, when a crc failure happens?  Will the packet be retried?  I have read all the documentation I can 
find on crc checking over Qnet and all that it says is that the packet is dropped.  

Thanks for your insight.

Andrew Boyd(deleted)

01/03/2011 3:11 PM

post80965

Re: Qnet and CRC checking

When a CRC error is detected, qnet will log an error in sloginfo which looks like this:

bad rxd packet - crc

and if you do this at the command line:

# cat /proc/qnetstats

you will see the L4 counter for "rxd bad L4" increase from zero.

The packet will be dropped and the remote end will time out and retransmit the packet.

Note that qnet also has the facility to hex dump the packet with the bad crc to sloginfo.  See the "dump_crc=X" qnet 
command line option.  This can help you figure out what's going on with the driver.

Return

The text you entered is not a valid object ID
More Information
Object IDs begin with an object prefix and end with a number. For example, if you enter
artf2345
the application will jump directly to an artifact with the ID artf2345. Some valid object prefixes are:
artf	for an artifact
doc	for a document
page	for a project page
topc	for a discussion topic
wiki	for a wiki page