threads - use them as much as you can

Ulf Wiger <>
Fri Dec 1 11:12:47 CET 2000


On Fri, 1 Dec 2000, Thomas Lindgren wrote:

>
>> In R7B (the current release) there is a new feature which introduces a pool
>> of native threads for i/o operations but this is disabled by default. This
>> will get around the hanging problem /.../ 
>
>Some web server research indicates that (on some OS:es) the entire OS
>process hangs on, say, disk I/O. The solution they proposed is to run
>disk I/O in a separate process. I'm not sure what Erlang/OTP does.

In OTP R7B, you can run disk I/O in a separate thread. Thus, if the
disk is slow, only the Erlang process requesting the I/O will have to
wait.

I'm using this in CCviewer, my web server/code browser. It made a
significant difference. Now, I'm using 10 I/O threads, and trying to
keep up with the maximum number of concurrent requests to the server
(so far, 10 simultaneous requests is the record, while the average is
1.1)

/Uffe

-- 
Ulf Wiger                                    tfn: +46  8 719 81 95
Senior System Architect                      mob: +46 70 519 81 95
Strategic Product & System Management    ATM Multiservice Networks
Data Backbone & Optical Services Division      Ericsson Telecom AB




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