Category Archives: Networking

Latency

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(To the tune of Yesterday, With apologies to all four Beatles and most sys admins)

Latency
It’s the signature of HPC
that is why it’s running endlessly
your process gates on Latency

This one, well
is embarrassingly parallel
that is why its running fast as hell
the render farm works just as well

Why’s it running slow
don’t you know the bottleneck
demands for some commands
will dictate your architect ect ecture

Here’s the scoop
This one’s nothing more than data soup
that you’re running through an endless loop
You probably should try Hadoop

(This might be the only one I tag as both Lyrics and Networking)

RFI: SPEGNO multiple requests

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From what we are seeing and what I’ve read, the browser seems to send a JSON request with no Auth info, and then the whole SPEGNO handshake takes place, turning what should be a single request response into (at a minimum) two.  It seems to me that we should be able to avoid that after the initial auth has taken place.

Is there any way to cache SPEGNO information such that successive JSON RPC calls provide the needed information automatically, instead of requiring multiple round trips per request?

Any Fedora people worked with this stuff and know how to optimize it?  Do I need to revert to a Cookie based approach?

interface2addr

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This little script will give you the ipv4 address for a given network interface, or list all of them if you leave the parameter blank:

#!/bin/bash

INTERFACE=$1

/sbin/ifconfig $INTERFACE | grep “inet addr” | cut -d\: -f 2 | cut -d” ” -f 1

Call it like this:

~/bin/interface2addr eth0