[mapserver-users] mapcache fastcgi

Wed Oct 17 05:34:30 PDT 2018

Hi,

In which way does the slowness appear? Is it when seeding or when serving from a pre-seeded cache? Can you give metrics about the difference in speed?

In this comparison the differences were rather small http://blog.sogeo.services/blog/2016/07/01/mapcache-disk-vs-sqlite.html

Also by the documentation the speed should be only "a bit slower"

The SQLite based caches are a bit slower than the disk based caches, and may have write-locking issues at seed time if a high number of threads all try to insert new tiles concurrently.

You wrote that SQLite cache is very slow for you which makes me think that there is something sub-optimal in your installation. First thing to check is if the SQLite database is on a fast disk.
If SQLite cache is slow then MBTiles cache should be slow as well but I would make a test to be sure.

-Jukka Rahkonen-

Lähettäjä: Sebastiano Laini [mailto:Sebastiano.Laini at BuchananComputing.co.uk]
Lähetetty: 17. lokakuuta 2018 15:00
Vastaanottaja: 'mapserver-users at lists.osgeo.org' <mapserver-users at lists.osgeo.org>
Kopio: Rahkonen Jukka (MML) <jukka.rahkonen at maanmittauslaitos.fi>
Aihe: RE: mapcache fastcgi

Is there a way to improve the speed and match the speed of the sqLite3 cache with the disk one?

We have 80 websites connected to MapCache and when I tried the sqLite3 I was testing it just on one website and on a complete different server with nothing in it.

Sebastiano Laini
Web Developer
Buchanan Computing
From: Sebastiano Laini
Sent: 17 October 2018 12:43
To: 'mapserver-users at lists.osgeo.org' <mapserver-users at lists.osgeo.org<mailto:mapserver-users at lists.osgeo.org>>
Cc: 'Rahkonen Jukka (MML)' <jukka.rahkonen at maanmittauslaitos.fi<mailto:jukka.rahkonen at maanmittauslaitos.fi>>
Subject: RE: mapcache fastcgi

Still it redirect you to that link, and btw it seems that mapcache can be used also as a fastCGI.

https://mapserver.org/mapcache/install.html#cgi-fastcgi-specific-instructions

Though is true that I'm reading now in the CMaker Builder section

MapCache can run as a FastCGI executable. Note that the overhead of FastCGI is non-negligible with respect to the throughput you may obtain with a native Apache module. The FastCGI build is less tested, and may lag behind the Apache module version on some minor details. YMMV.

Sebastiano Laini
Web Developer
Buchanan Computing

From: Rahkonen Jukka (MML) [mailto:jukka.rahkonen at maanmittauslaitos.fi]
Sent: 17 October 2018 12:39
To: Sebastiano Laini <Sebastiano.Laini at BuchananComputing.co.uk<mailto:Sebastiano.Laini at BuchananComputing.co.uk>>; 'mapserver-users at lists.osgeo.org' <mapserver-users at lists.osgeo.org<mailto:mapserver-users at lists.osgeo.org>>
Subject: VS: mapcache fastcgi

Hi,

That documentation is about Mapserver, Mapcache is another software. It does belong to the same Mapserver but is not the same.

MapCache is documented here:
https://mapserver.org/mapcache/index.html#mapcache

-Jukka Rahkonen-

Lähettäjä: Sebastiano Laini [mailto:Sebastiano.Laini at BuchananComputing.co.uk]
Lähetetty: 17. lokakuuta 2018 14:33
Vastaanottaja: 'mapserver-users at lists.osgeo.org' <mapserver-users at lists.osgeo.org<mailto:mapserver-users at lists.osgeo.org>>
Kopio: Rahkonen Jukka (MML) <jukka.rahkonen at maanmittauslaitos.fi<mailto:jukka.rahkonen at maanmittauslaitos.fi>>
Aihe: RE: mapcache fastcgi

Well, for what I can read in the documentation of mapserver:

https://mapserver.org/optimization/fastcgi.html

FastCGI is a protocol for keeping cgi-bin style web applications running as a daemon to take advantage of preserving memory caches, and amortizing other high startup costs (like heavy database connections) over many requests.

It seems that using mapcache as fastCGI over apache modules it that should improve speed also.

Sebastiano Laini
Web Developer
Buchanan Computing

From: Rahkonen Jukka (MML) [mailto:jukka.rahkonen at maanmittauslaitos.fi]
Sent: 17 October 2018 12:30
To: Sebastiano Laini <Sebastiano.Laini at BuchananComputing.co.uk<mailto:Sebastiano.Laini at BuchananComputing.co.uk>>; 'mapserver-users at lists.osgeo.org' <mapserver-users at lists.osgeo.org<mailto:mapserver-users at lists.osgeo.org>>
Subject: Re: mapcache fastcgi

Hi,

Could you explain your plan with some more details? What I have understood is that you have experienced that SQLite cache is slower than disk cache in your environment.

What I do not understand is what you are going to reach by running Mapcache as fastcgi instead of running it as Apache module which should be the faster option, and if this has some connection with the SQLite cache vs. disk cache comparison. Do you guess that fastcgi woud make SQLite cache faster?

-Jukka Rahkonen-

Lähettäjä: mapserver-users [mailto:mapserver-users-bounces at lists.osgeo.org] Puolesta Sebastiano Laini
Lähetetty: 17. lokakuuta 2018 12:16
Vastaanottaja: 'mapserver-users at lists.osgeo.org' <mapserver-users at lists.osgeo.org<mailto:mapserver-users at lists.osgeo.org>>
Aihe: [mapserver-users] mapcache fastcgi

Hi all,

In the end I tried MapCache with sqlite3 cache but it's very slow compared with the disk cache, so I want to setup MapCache with fastCGI on CentOS 7.

I don't understand what I need to install as the fastCGI link in the documentation is broken and I don't know if is up to date.

I already have apache fgcid installed from default in the httpd folder and I use PHP in fastCGI in all the domains, so I'm sure that fastCGI it works, though, I still need the fastCGI library? How can I install it in CentOS 7?

In my apache conf I've already added the lines to load the mapcache module and the mapcache.xml file

LoadModule mapcache_module    modules/mod_mapcache.so

<IfModule mapcache_module>
   <Directory /path/to/directory>
      Require all granted
   </Directory>
   MapCacheAlias /mapcache "/path/to/directory/mapcache.xml"
</IfModule>

I need to leave the previous configuration and add these new lines in the conf files?

FcgidInitialEnv "MAPCACHE_CONFIG_FILE" "/path/to/mapcache/mapcache.xml

<IfModule mod_fcgid.c>
   IPCCommTimeout 120
   MaxProcessCount 10
   FcgidInitialEnv "MAPCACHE_CONFIG_FILE" "/path/to/mapcache/mapcache.xml"
   <Location /map.fcgi>
      Order Allow,Deny
      Allow from all
      SetHandler fcgid-script
   </Location>
  ScriptAlias /map.fcgi "/path/to/mapcache/src/mapcache"
</IfModule>

And then instead of http://myserver/mapcache I need to use http://myserver/fcgi-bin to access mapcache fcgi?

Regards,

Sebastiano Laini
Web Developer
Buchanan Computing
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