Comments for Humboldt Solutions Ltd http://www.humboldt.co.uk Software Development and Consulting Fri, 18 Jun 2010 23:44:42 +0000 hourly 1 http://wordpress.org/?v=3.0.5 Comment on A Working TFTP Server for Multi-Homed Linux Systems by Ean http://www.humboldt.co.uk/2008/11/a-working-tftp-server-for-multi-homed-linux-systems.html/comment-page-1#comment-3879 Ean Fri, 18 Jun 2010 23:44:42 +0000 http://www.humboldt.co.uk/?p=25#comment-3879 Thanks for the concise summary of the issue! My searching didn't turn up the Debian bug, but did turn up your page and it was a huge help. Fyi, dnsmasq's TFTP server does support multi-homed servers, but it doesn't support ipv6. If you need both multi-homing and ipv6, I've had luck hand-applying the patch from the debian bug thread above to the latest tftpd-hpa. Ean Thanks for the concise summary of the issue! My searching didn’t turn up the Debian bug, but did turn up your page and it was a huge help.

Fyi, dnsmasq’s TFTP server does support multi-homed servers, but it doesn’t support ipv6. If you need both multi-homing and ipv6, I’ve had luck hand-applying the patch from the debian bug thread above to the latest tftpd-hpa.
Ean

]]> Comment on Slow Reboots of NFS Server by K.Bala http://www.humboldt.co.uk/2006/02/slow-reboots-of-nfs-server.html/comment-page-1#comment-3599 K.Bala Tue, 27 Apr 2010 12:54:07 +0000 http://testwww.humboldt.co.uk/2006/02/slow-reboots-of-nfs-server.html#comment-3599 Great its worked for me too.. su - rm /var/lib/nfs/rmtab reboot NFS started instantaneously rather than taking several minutes. Thanks, K.Bala Great its worked for me too..

su -
rm /var/lib/nfs/rmtab
reboot

NFS started instantaneously rather than taking several minutes.

Thanks,
K.Bala

]]> Comment on The Mystery of ProxyPassReverse by MIke http://www.humboldt.co.uk/2009/02/the-mystery-of-proxypassreverse.html/comment-page-1#comment-3435 MIke Fri, 16 Apr 2010 22:11:53 +0000 http://www.humboldt.co.uk/?p=119#comment-3435 Thank you, thank you, thank you. Everybody else neglected this very important part of the configuration. I actually needed both, but now it works like a charm. Thank you, thank you, thank you. Everybody else neglected this very important part of the configuration. I actually needed both, but now it works like a charm.

]]> Comment on The Mystery of ProxyPassReverse by Adrian Cox http://www.humboldt.co.uk/2009/02/the-mystery-of-proxypassreverse.html/comment-page-1#comment-2657 Adrian Cox Sat, 06 Jun 2009 08:34:54 +0000 http://www.humboldt.co.uk/?p=119#comment-2657 The ProxyPassReverse is still required to rewrite the headers in the redirect, whether you use AJP or HTTP. To get a clearer view of what is going on, install <a href="http://getfirebug.com/" rel="nofollow">Firebug</a> and look at the network activity during the redirect. You should see that without the ProxyPassReverse line, an application redirect to "test.jsp" will become a HTTP redirect to "http://www.example.com/jspdir/test.jsp". The ProxyPassReverse line will translate that redirect to the correct "http://www.example.com/test.jsp". The ProxyPassReverse is still required to rewrite the headers in the redirect, whether you use AJP or HTTP. To get a clearer view of what is going on, install Firebug and look at the network activity during the redirect.

You should see that without the ProxyPassReverse line, an application redirect to “test.jsp” will become a HTTP redirect to “http://www.example.com/jspdir/test.jsp”. The ProxyPassReverse line will translate that redirect to the correct “http://www.example.com/test.jsp”.

]]> Comment on The Mystery of ProxyPassReverse by Rafael Santini http://www.humboldt.co.uk/2009/02/the-mystery-of-proxypassreverse.html/comment-page-1#comment-2656 Rafael Santini Sat, 06 Jun 2009 04:19:54 +0000 http://www.humboldt.co.uk/?p=119#comment-2656 I would like to know why "ProxyPass / http://localhost/jspdir" does not works with sendRedirect. What is the difference between ajp and http? To me, this appear a bug with proxy_http. I would like to know why “ProxyPass / http://localhost/jspdir” does not works with sendRedirect. What is the difference between ajp and http? To me, this appear a bug with proxy_http.

]]> Comment on The Mystery of ProxyPassReverse by Rafael Santini http://www.humboldt.co.uk/2009/02/the-mystery-of-proxypassreverse.html/comment-page-1#comment-2655 Rafael Santini Sat, 06 Jun 2009 04:05:19 +0000 http://www.humboldt.co.uk/?p=119#comment-2655 Finally, I found an example that works! Finally, I found an example that works!

]]> Comment on A Working TFTP Server for Multi-Homed Linux Systems by Simon Kelley http://www.humboldt.co.uk/2008/11/a-working-tftp-server-for-multi-homed-linux-systems.html/comment-page-1#comment-2654 Simon Kelley Thu, 28 May 2009 12:05:52 +0000 http://www.humboldt.co.uk/?p=25#comment-2654 Just a quick correction about dnsmasq. It can use either of the two approaches to UDP source control that you describe. By default it does the IP_PKTINFO thing (and its equivalent for the other supported platforms) but can be configured to use the multiple-socket solution with --bind-interfaces. HTH Simon. Just a quick correction about dnsmasq. It can use either of the two approaches to UDP source control that you describe. By default it does the IP_PKTINFO thing (and its equivalent for the other supported platforms) but can be configured to use the multiple-socket solution with –bind-interfaces.

HTH

Simon.

]]> Comment on Slow Reboots of NFS Server by ChrisP http://www.humboldt.co.uk/2006/02/slow-reboots-of-nfs-server.html/comment-page-1#comment-6 ChrisP Wed, 25 Jul 2007 02:25:00 +0000 http://testwww.humboldt.co.uk/2006/02/slow-reboots-of-nfs-server.html#comment-6 Excellent - worked for me.<br/><br/>su -<br/>rm /var/lib/nfs/rmtab<br/>reboot<br/><br/>NFS started instantaneously rather than taking several minutes.<br/><br/>Thanks,<br/>Chris. Excellent – worked for me.su -rm /var/lib/nfs/rmtabrebootNFS started instantaneously rather than taking several minutes.Thanks,Chris.

]]> Comment on Embedded Theora Video by Timothy B. Terriberry http://www.humboldt.co.uk/2006/02/embedded-theora-video.html/comment-page-1#comment-5 Timothy B. Terriberry Fri, 01 Dec 2006 18:09:00 +0000 http://testwww.humboldt.co.uk/2006/02/embedded-theora-video.html#comment-5 The real problem, as I saw it, was not the raster/Hilbert curve ordering (though this certainly introduces many complexities in the encoder; the decoder is not as bad), but the fact that coefficients are ordered by their frequency first, and the block they belong to second, meaning that if the 63rd coefficient in a block is non-zero, you need to decode virtually all the coefficients in the frame before you can decode that one block.<br/><br/>This structure actually helps avoid the raster order problem for DC prediction, because you can undo the DC prediction after decoding just the DC coefficients, i.e., on 1/64th of the final image data, which often fits entirely in cache (at 640x480 it's less than 16k of data).<br/><br/>The loop filter problem can similarly be handled by applying it (with a one block row delay) after each super block row is decoded. This requires slightly more cache (just under 64k of image data at 640x480, plus additional overhead for the coefficients that were decoded), but should still fit well within the 256K L2 cache on your DSP.<br/><br/>The <a HREF="http://svn.xiph.org/trunk/theora-exp/" REL="nofollow">theora-exp</a> decoder does both these things, to good effect. The spec describes everything as separate processes for conceptual simplicity, but to get good preformance they really need to be pipelined.<br/><br/>For the loop filter at larger resolutions, you could (if you're careful about it), process 3/4 of each superblock (with a one block column delay) immediately after decoding it, without waiting for the entire row to finish. Then you only need to cache one row of block data between superblock rows. The real problem, as I saw it, was not the raster/Hilbert curve ordering (though this certainly introduces many complexities in the encoder; the decoder is not as bad), but the fact that coefficients are ordered by their frequency first, and the block they belong to second, meaning that if the 63rd coefficient in a block is non-zero, you need to decode virtually all the coefficients in the frame before you can decode that one block.This structure actually helps avoid the raster order problem for DC prediction, because you can undo the DC prediction after decoding just the DC coefficients, i.e., on 1/64th of the final image data, which often fits entirely in cache (at 640×480 it’s less than 16k of data).The loop filter problem can similarly be handled by applying it (with a one block row delay) after each super block row is decoded. This requires slightly more cache (just under 64k of image data at 640×480, plus additional overhead for the coefficients that were decoded), but should still fit well within the 256K L2 cache on your DSP.The theora-exp decoder does both these things, to good effect. The spec describes everything as separate processes for conceptual simplicity, but to get good preformance they really need to be pipelined.For the loop filter at larger resolutions, you could (if you’re careful about it), process 3/4 of each superblock (with a one block column delay) immediately after decoding it, without waiting for the entire row to finish. Then you only need to cache one row of block data between superblock rows.

]]> Comment on Slow Reboots of NFS Server by Anonymous http://www.humboldt.co.uk/2006/02/slow-reboots-of-nfs-server.html/comment-page-1#comment-4 Anonymous Mon, 29 May 2006 04:00:00 +0000 http://testwww.humboldt.co.uk/2006/02/slow-reboots-of-nfs-server.html#comment-4 Ah. This post solved my slow nfs startup problem, which has been annoying me. Thanks for the author. Ah. This post solved my slow nfs startup problem, which has been annoying me. Thanks for the author.

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