Skip to main content

nice ssh2 in php

Image
By User



I have a php script that transfers a bunch of files between servers with the pecl ssh2 extension ( ssh2_sftp_* for the most part). These files add up to about a gig or so each time. The bandwidth is throttled, so that's not a problem. The problem is the ssh2 process eats up a ton of CPU and actually slows down the server during the upload. Is there any way to start the ssh process at a certain nice level? If php's ssh2 functions create a new process (I'm not sure that they do), is it possible to find and renice this process once it's been started from within the php script? Since the ssh2 functions are not threaded, there probably isn't.





Basically, I'd like PHP's ssh2 functions not to use so much CPU. It seems like proc_nice will do this, but it looks like I may have to use ionice instead. How can I do that?


Labels:

Comments

  1. Tips For AllJanuary 17, 2012 at 1:25 AM

    A short look at the sources of PEAR::ssh2 shows, that the SSH2 functions are executed in-thread and in-process, so there is no real straight-forward way. Here are a two possibilities:


    If you are on a multi-process apache use proc_nice to reduce
    priority, then apache_child_terminate to kill the process.
    Use proc_open or friends to open a shellscript of the type


    #!/bin/bash
    read SRCFILE
    read DSTFILE
    nice scp "$SRCFILE" "$DSTFILE"


    We use the latter for quite a lot of CPU-hogging tasks

    ReplyDelete

Post a Comment

Popular posts from this blog

Why is this Javascript much *slower* than its jQuery equivalent?

By User
I have a HTML list of about 500 items and a "filter" box above it. I started by using jQuery to filter the list when I typed a letter (timing code added later): $('#filter').keyup( function() { var jqStart = (new Date).getTime(); var search = $(this).val().toLowerCase(); var $list = $('ul.ablist > li'); $list.each( function() { if ( $(this).text().toLowerCase().indexOf(search) === -1 ) $(this).hide(); else $(this).show(); } ); console.log('Time: ' + ((new Date).getTime() - jqStart)); } ); However, there was a couple of seconds delay after typing each letter (particularly the first letter). So I thought it may be slightly quicker if I used plain Javascript (I read recently that jQuery's each function is particularly slow). Here's my JS equivalent: document.getElementById('filter').addEventListener( 'keyup', function () { var jsStart = (new Date).getTime()...
3 comments
Read more

Is it possible to have IF statement in an Echo statement in PHP

By User
Thanks in advance. I did look at the other questions/answers that were similar and didn't find exactly what I was looking for. I'm trying to do this, am I on the right path? echo " <div id='tabs-".$match."'> <textarea id='".$match."' name='".$match."'>". if ($COLUMN_NAME === $match) { echo $FIELD_WITH_COLUMN_NAME; } else { } ."</textarea> <script type='text/javascript'> CKEDITOR.replace( '".$match."' ); </script> </div>"; I am getting the following error message in the browser: Parse error: syntax error, unexpected T_IF Please let me know if this is the right way to go about nesting an IF statement inside an echo. Thank you.
5 comments
Read more