Using Redux to serve images on myamiweb¶

Before you begin:
Redux is new for CentOS 6 (PHP 5.3).
If you want to install Appion/Leginon 2.2 on CentOS 5, you do not need to install Redux. Instead, you must follow the directions to Install the MRC PHP Extension.

Installation¶

1. Follow Web_Server_Installation but ignore warning on not using php 5.3
2. Install myami-redux branch of myami on the webserver machine.
   • Install redux prerequisites as found in its README file
   • Redux needs write permission at its installation location to write fftw wisdom file.
   • Install python filesystem abstraction for redux caching like this:
     

     sudo easy_install fs
     

Configurations:¶

configure redux¶

> cd /YourMyamDownload/redux
> cp redux.cfg.template redux.cfg

* You can also copy it to /etc/myami/redux.cfg if you prefer.

• Turn on redux caching if desired,
  

  [cache]
  enable: yes
  path: /var/cache/myami/redux
  disksize:  500
  memsize: 500
  

  
  You need to make sure the cache path exists and writable by the user that starts the redux server (reduxd)
  • Input the desired disk_cache_path, disk_cache_size, and mem_cache_size in the next few lines
  • Create the disk_cache_path before running redux if cache will be used

Assign redux server in myamiweb¶

• At myamiweb/config.php
  

  define('SERVER_HOST',"localhost")
  

Test Installation¶

1. Using Redux to do simple input output (simple client with no reduxd server needed):

   redux --filename=test.jpg --oformat=PNG > test.png

   Make sure the resulting test.png is in fact an image and not an error message.
2. Run the server: run the following on a command line:

   reduxd

   leave it running for the following...
3. Test command line client connecting to the server

   redux --server_host=localhost --filename=test.jpg --oformat=PNG > test.png

   Note: The input file name is from the perspective of the reduxd server, so be sure to give it an absolute path (unlike the first test, which was not accessing the server)

Using redux server with myamiweb¶

1. start reduxd server if not already running from the above test:

   reduxd

2. click on "[test dataset]" on your main myamiweb home page, or go directly to the URL: myamiweb/viewerxml.php
3. test by accessing your own images from Leginon in myamiweb/imageviewer.php

starting reduxd at boot¶

sudo cp -v myami/redux/init.d/reduxd /etc/init.d/
sudo service reduxd start

Alternative reduxd installation on file server rather than web server¶

This approach is less tested, but has been found necessary in the case of a very high load system (multiple microscopes acquiring data, multiple processing jobs, multiple web clients and servers, etc). The problem has been that all of this demand for image I/O is occuring over NFS, and the NFS server is not coping with the high demand. One solution we have been investigating is to run reduxd directly on the file server rather than the web server. This means reduxd has direct access to the image files (not through NFS) and the web server now accesses reduxd over the network rather than locally. This has two potential benefits: 1) less load on the NFS server, 2) only transferring JPEGs over the network, not MRCs.

How to do it:

1. Install required myami components on the file server, at least pyami, sinedon, numextension, redux, leginon, modules, and any other 3rd part packages required by those.
2. (optional) edit init.d/reduxd and use the optional high priority command line (see comment in that file)
3. Configure redux.cfg on file server and start reduxd
4. On web server, configure config.php: turn off all caching options, set redux server host to be the file server
5. skip imcache as described below, since this also uses redux locally and accesses images over NFS

Using imcache to cache mrc images as jpeg images of the default size on myamiweb¶

imcache uses redux and replaces the old myamiweb caching system that used mrc2any. It queries the database leginondata and check the cache_path for uncached images and convert them to jpeg images. These jpeg images can be 94 x smaller than the mrc 4kx4k image. Therefore, using imcache will significantly increase the image load time from the image viewer. A default size power spectrum image is also cached.

Installation¶

1. Follow Web_Server_Installation with modification for redux.
2. Install pyami, sinedon, redux on the webserver machine
3. Configure sinedon.cfg for your database
4. imcache can found in your myamiweb installation in the folder myamiweb/imcache/

Configurations:¶

configure imcache¶

> cd /YourMyamiWeb/imcache
> edit imcacheconfig.py

Modify the line

cache_path = '/srv/cache/myamiweb'

to the path you want to use as the base path for the cache to be stored. The path must exist and writable by whoever starts imcached

Assign the same cache path in myamiweb¶

• At myamiweb/config.php
  

  define('ENABLE_CACHE', true);
  define('CACHE_PATH',"/srv/cache/myamiweb");
  

h2 Test Installation

1. Start imcached in its installed location with the reverse order caching
   

   ./imcached r
   

   
   If you have acquired any Leginon images prior to this, imcached will start converting them into jpeg.
2. View a cached image in the imageviewer while checking redux log. jpeg, not mrc image should be requested by the imageviwer.

Start imcache during data collection¶

1. Start imcached in its installed location with the forward order caching in the background
   

   sudo nohup ./imcached f > /var/log/imcached.f
   

2. Wait for the first image to be cached before starting the reverse caching
   

   sudo nohup ./imcached r > /var/log/imcached.r