I have used varnish quite a bit on my LAMP stacks and this deff helps quite a bit out for static files to serve up and keeps the load off of apache.

I hear good things about nginx static file caching so is their a need to put varnish up a head of it?

Nginx

Hi,

Turned out I can't replicate the problem defined down there, but I guess it would've been solved thanks to Advagg. I now have an entirely different problem.

I have several virtualhosts on Apache, some of them will not be served with Varnish, but all listen to port 80.

So, the question is, how can I have Apache listening on port 80 for some virtualhosts, and Varnish listening on port 80 for other virtualhosts?

I'm having a weird problem and I can't get to solve it.

Firstly, here is the setup :

• Debian Squeeze
• Apache 2.2.16
• PHP5-fpm
• Varnish 3.0.2
• Pressflow 6

I have a Drupal setup with a vhost correctly configured on port 80. I've used the default.vcl file from lullabot (available here) with the status.php file. I had to make a little change to the default.vcl file because of a syntax error (changes from 2.x versions to 3.x).

I changed this line :

<?php
set req.http.Cookie = ";" req.http.Cookie;
?>

To :

<?php
set req.http.Cookie = ";" + req.http.Cookie;
?>

Otherwise, I get this error when launching Varnish :

<?php
Message from VCC-compiler:
Expected ';' got 'req.http.Cookie'
(program line 174), at
('input' Line 108 Pos 31)
    set req.http.Cookie = ";" req.http.Cookie;
------------------------------###############-

Running VCC-compiler failed, exit 1

VCL compilation failed
?>

Anyway, when I launch Varnish on port 8080, or anything else than 80, it works perfectly. I can get to http://www.domain.com:8080 and everything loads fast. I can also see with varnishlog that it's working correctly.

The problem is when I change the port of my Drupal setup to 8080 (I've also tried 81). I also change Varnish to listen on port 80, and it gets weird.

I can access the website on port 80, but the css/js files don't get loaded because of 404 errors. Also, varnishlog doesn't output anything.

I really don't get what's going on... Any help would be greatly appreciated :)

P.S. : I'm using the Varnish module for Drupal, On the administration page, Varnish answers correctly.

High performance

Environment

I’m in the process of setting up a CentOS VPS running a moderately used D6 site (approximately 1000 visits/day). I’ve installed the entire stack including Apache, MySQL 5.5, and PHP 5.3. The VPS has a 3.6Ghz dedicated CPU, and 2.2GB Memory (provided through VPS.net)

I’ve installed Memcache and APC, which seem to be working fine. I’ve tuned MySQL using mysqltuner.pl and tuning-primer.sh. My current my.cnf is posted below. All tables are InnoDB.

Problem

My current issue is that when logged in, various pages tend to be very slow (occasionally taking over 10 seconds to generate). I have devel’s query log functionality enabled and it does not seem to be one specific query that causes the problem- it seems to be random queries that sometimes take several seconds. This especially seems to happen with admin pages.

Indexes?

After doing a bit of research, I believe I need to index various database tables. This site has 22 content types and 73 fields defined. My questions is how do I know what tables to index and what fields to index? I've looked into the DBtuner module, but that only shows core fields (as opposed to the CCK fields).

Does anyone have any tips or suggestions?

Below is my current my.cnf

[mysqld]

#added MH 1-17-12
#comment this out after troubleshooting
log-queries-not-using-indexes

## General
datadir                         = /var/lib/mysql
tmpdir                          = /var/lib/mysqltmp
socket                          = /var/lib/mysql/mysql.sock
skip-name-resolve
sql-mode                        = NO_ENGINE_SUBSTITUTION
#event-scheduler                = 1

## Cache
thread-cache-size               = 16
table-open-cache                = 4096
table-definition-cache          = 2048
query-cache-size                = 96M
query-cache-limit               = 5M

## Per-thread Buffers
sort-buffer-size                = 1M
read-buffer-size                = 1M
read-rnd-buffer-size            = 1M
join-buffer-size                = 2M

## Temp Tables
tmp-table-size                  = 256M
max-heap-table-size             = 256M

## Networking
back-log                        = 100
max-connections                 = 25
max-connect-errors              = 10000
max-allowed-packet              = 16M
interactive-timeout             = 3600
wait-timeout                    = 600
bind-address         = 127.0.0.1 #added mh 1-24-12 for phpmyadmin

### Storage Engines
#default-storage-engine         = InnoDB
innodb                          = FORCE

## MyISAM
key-buffer-size                 = 64M
myisam-sort-buffer-size         = 128M

## InnoDB

innodb-log-file-size           = 100M
innodb-log-buffer-size         = 4M
innodb-file-per-table          = 1
#innodb-open-files              = 300
innodb_flush_log_at_trx_commit  = 2
innodb_additional_mem_pool_size = 20M

# InnoDB caches. Increase if needed (defaults to 8M, should use as much as is available). MH 1-25-12
innodb_buffer_pool_size = 1024M
innodb_flush_method = O_DIRECT


## Replication
server-id                       = 1
#log-bin                        = /var/lib/mysqllogs/bin-log
#relay-log                      = /var/lib/mysqllogs/relay-log
relay-log-space-limit           = 16G
expire-logs-days                = 7
#read-only                      = 1
#sync-binlog                    = 1
#log-slave-updates              = 1
#binlog-format                  = STATEMENT
#auto-increment-offset          = 1
#auto-increment-increment       = 2

## Logging
log-output                      = FILE
slow-query-log                  = 1
slow-query-log-file             = /var/lib/mysqllogs/slow-log
log-slow-slave-statements
long-query-time                 = 2

[mysqld_safe]
log-error                       = /var/log/mysqld.log
open-files-limit                = 65535

[mysql]
no-auto-rehash

High performance

Environment

I’m in the process of setting up a CentOS VPS running a moderately used D6 site (approximately 1000 visits/day). I’ve installed the entire stack including Apache, MySQL 5.5, and PHP 5.3. The VPS has a 3.6Ghz dedicated CPU, and 2.2GB Memory (provided through VPS.net)

I’ve installed Memcache and APC, which seem to be working fine. I’ve tuned MySQL using mysqltuner.pl and tuning-primer.sh. My current my.cnf is posted below. All tables are InnoDB.

Problem

My current issue is that when logged in, various pages tend to be very slow (occasionally taking over 10 seconds to generate). I have devel’s query log functionality enabled and it does not seem to be one specific query that causes the problem- it seems to be random queries that sometimes take several seconds. This especially seems to happen with admin pages.

Indexes?

After doing a bit of research, I believe I need to index various database tables. This site has 22 content types and 73 fields defined. My questions is how do I know what tables to index and what fields to index? I've looked into the DBtuner module, but that only shows core fields (as opposed to the CCK fields).

Does anyone have any tips or suggestions?

Below is my current my.cnf

[mysqld]

#added MH 1-17-12
#comment this out after troubleshooting
log-queries-not-using-indexes

## General
datadir                         = /var/lib/mysql
tmpdir                          = /var/lib/mysqltmp
socket                          = /var/lib/mysql/mysql.sock
skip-name-resolve
sql-mode                        = NO_ENGINE_SUBSTITUTION
#event-scheduler                = 1

## Cache
thread-cache-size               = 16
table-open-cache                = 4096
table-definition-cache          = 2048
query-cache-size                = 96M
query-cache-limit               = 5M

## Per-thread Buffers
sort-buffer-size                = 1M
read-buffer-size                = 1M
read-rnd-buffer-size            = 1M
join-buffer-size                = 2M

## Temp Tables
tmp-table-size                  = 256M
max-heap-table-size             = 256M

## Networking
back-log                        = 100
max-connections                 = 25
max-connect-errors              = 10000
max-allowed-packet              = 16M
interactive-timeout             = 3600
wait-timeout                    = 600
bind-address         = 127.0.0.1 #added mh 1-24-12 for phpmyadmin

### Storage Engines
#default-storage-engine         = InnoDB
innodb                          = FORCE

## MyISAM
key-buffer-size                 = 64M
myisam-sort-buffer-size         = 128M

## InnoDB

innodb-log-file-size           = 100M
innodb-log-buffer-size         = 4M
innodb-file-per-table          = 1
#innodb-open-files              = 300
innodb_flush_log_at_trx_commit  = 2
innodb_additional_mem_pool_size = 20M

# InnoDB caches. Increase if needed (defaults to 8M, should use as much as is available). MH 1-25-12
innodb_buffer_pool_size = 1024M
innodb_flush_method = O_DIRECT


## Replication
server-id                       = 1
#log-bin                        = /var/lib/mysqllogs/bin-log
#relay-log                      = /var/lib/mysqllogs/relay-log
relay-log-space-limit           = 16G
expire-logs-days                = 7
#read-only                      = 1
#sync-binlog                    = 1
#log-slave-updates              = 1
#binlog-format                  = STATEMENT
#auto-increment-offset          = 1
#auto-increment-increment       = 2

## Logging
log-output                      = FILE
slow-query-log                  = 1
slow-query-log-file             = /var/lib/mysqllogs/slow-log
log-slow-slave-statements
long-query-time                 = 2

[mysqld_safe]
log-error                       = /var/log/mysqld.log
open-files-limit                = 65535

[mysql]
no-auto-rehash

High performance

Hi All,

I just thought you might be interested to see some performance benchmarks that I've produced recently whilst doing some work porting the Authcache module to D7.

I think the results are pretty "encouraging". What do you think :) ?

Benchmark Requests Concurrency Total
Time Taken/s Requests/s Avg
Time Per
Request/ms Time Per
Request
(across all)/ms Longest
Request/ms Completed
Requests Failed
Requests Static Html 1000 50 0.22 4540.56 11.012 0.22 13 1000 0 Anonymous Stock Drupal 1000 50 6.38 156.75 318.98 6.38 721 1000 0 Anonymous Authcache Drupal 1000 50 0.794 1259.52 39.698 0.794 81 1000 0 Static Html 1000 125 0.236 4237.05 29.502 0.236 35 1000 0 Anonymous Stock Drupal 1000 125 5.453 183.39 681.618 5.453 2523 1000 0 Anonymous Authcache Drupal 1000 125 0.767 1303.55 95.892 0.767 125 1000 0 Authenticated Stock Drupal 20 1 18.815 1.06 940.729 940.729 1101 20 0 Authenticated Stock Drupal 20 2 9.453 2.12 945.32 472.66 1130 20 0 Authenticated Stock Drupal 20 5 5.82 3.44 1454.978 290.978 1663 20 0 Authenticated Stock Drupal 50 10 14.035 3.56 2807.047 280.705 3393 50 0 Authenticated Authcache Drupal 1000 1 2.646 377.99 2.646 2.646 8 1000 0 Authenticated Authcache Drupal 1000 125 0.806 1240.86 100.737 0.806 141 1000 0 Authenticated Authcache Drupal 1000 250 4.527 220.87 1131.87 4.527 4520 1000 0 Authenticated Authcache Drupal 1000 500 12.217 81.85 6108.72 12.217 12213 1000 0

All tests performed on quad core Q6600 processor with 8GB RAM, solid state SATA hard disk running Apache, APC and PHP 5.3 and Drupal 7.10

High performance

My Nginx setup, granted very basic start to it, no real caching set up yet... LAMP has really no special additions to it kinda a out of the box install.

Drupal sets ups are clones on both systems.

command for testing on both ab -c10 -n1000 http://localhost/

nginx result

Server Software:        nginx/1.0.9
Server Hostname:        localhost
Server Port:            80

Document Path:          /
Document Length:        3255 bytes

Concurrency Level:      10
Time taken for tests:   78.190 seconds
Complete requests:      1000
Failed requests:        0
Write errors:           0
Non-2xx responses:      1000
Total transferred:      3602000 bytes
HTML transferred:       3255000 bytes
Requests per second:    12.79 [#/sec] (mean)
Time per request:       781.900 [ms] (mean)
Time per request:       78.190 [ms] (mean, across all concurrent requests)
Transfer rate:          44.99 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   1.0      0      16
Processing:    75  781 631.6    709    8783
Waiting:       75  781 631.5    709    8782
Total:         75  781 632.2    709    8794

Percentage of the requests served within a certain time (ms)
  50%    709
  66%    752
  75%    770
  80%    778
  90%    805
  95%   1690
  98%   2690
  99%   3732
100%   8794 (longest request)

Apache2 Results

Server Software:        Apache/2.2.14
Server Hostname:        localhost
Server Port:            80

Document Path:          /
Document Length:        3283 bytes

Concurrency Level:      10
Time taken for tests:   25.926 seconds
Complete requests:      1000
Failed requests:        0
Write errors:           0
Non-2xx responses:      1000
Total transferred:      3671000 bytes
HTML transferred:       3283000 bytes
Requests per second:    38.57 [#/sec] (mean)
Time per request:       259.258 [ms] (mean)
Time per request:       25.926 [ms] (mean, across all concurrent requests)
Transfer rate:          138.28 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   2.3      0      39
Processing:   155  259  43.7    250     751
Waiting:      155  246  41.2    238     731
Total:        155  259  43.8    250     751

Percentage of the requests served within a certain time (ms)
  50%    250
  66%    255
  75%    259
  80%    269
  90%    298
  95%    305
  98%    317
  99%    354
100%    751 (longest request)

im a bit confused because from everything im reading nginx should be faster..

any thoughts? I know its hard to debug but just my first steps starting from scratch..

Nginx

We are looking for a Drupal engineer to review an existing site and offer performance and scalability recommendations to improve site performance.

The existing architecture includes Drupal 6, pound load balancing, MySQL database, memcache and APC. Existing site traffic levels include: 1.5-1.75 million pages, 10-15 million hits and 140-150GB bandwidth per month. Further details to be provided upon request.

The candidate should have a proven track record in this area and be able to furnish references upon request.

Thanks!

DevOps

This is not exclusively "Drupal related", but it's still useful if you want to properly find bottlenecks during a benchmark.
I want to do a test with Ab (Apache Benchmark) and I would like to monitor the memory and CPU usage during that test. What do you use for that? top command line tool?

High performance

Experienced Drupal Developer required to develop & maintain Drupal based sites
Agile / Scrum Methodology experience
Experienced in other frameworks desirable (but not essential)
Project experience of applying 'continuous integration' process (highly beneficial)
Good communication
6 Month Contract with high chance of extension

Please contact Amit Phakey on 0203 326 4110 / amit.phakey@parallelconsulting.com for more information.

London

I created a simple distro to play with MongoDB. Introducing MongoDrop

It uses the features for blocks, cache, field storage, and sessions.

I found problems with mongodb_watchdog that I couldn't figure out right away. I haven't looked at mongodb_queue yet.

Let me know what you think :)

MongoDB

Interesting announcement from Amazon today: managed NoSQL via their DynamoDB: http://aws.amazon.com/dynamodb

More details:
http://allthingsdistributed.com/2012/01/amazon-dynamodb.html

The interesting part of this is the data being stored on SSD, low latency, and the ability to pre-provision capacity and usage. My initial thought about this as it applies to Drupal would be along the lines of the mongodb project. IE, a Drupal module and API to enable certain tables to be stored and queried from a DynamoDB database.

I'm wondering specifically how well this would work for cache tables. Yes you can get memcache as a service but it's pretty expensive for what you get and you are charged hourly (smallest on-demand instance would be $69/mo and that's just for the cache). With DynamoDB, it could be a very low cost way of scaling out caching - especially for sites that are already using Amazon for hosting Drupal.

I'd be interested in hearing thoughts about this. I'm not planning on doing it, just throwing out an idea.

Amazon Web Services (S3, EC2)

We are in the process of using drupal with our new game server, this server will read and write a lot of the users game data, We have chosen to go with the basic pressflow and minimal modules enabled, some custom ones that work with the services api (its how we communicate with the client and server with JSON).

Someone mentioned to me that and im still trying to figure out the formula of well with a pure drupal site optimized you can only have so many concurrent users hitting the db before apache/php bottle neck comes in.

Btw is their a good formula or a way to test what you can push before apache/php start to eat up the memory and start to get close to blowing up or responding slowly?

Someone mentioned using a event driven framework such as node.js or twisted could end up taking up some of the heavy lifting of hundreds of thousands concurrent users to another db while working along side with Drupal.

Anyhow anyone have experience of off loading some load on Drupal with another framework?

High performance

I'm interested in finding out how people are configuring Drupal sites to make the best use of multiple memcache servers and distinct machines.

Topologies I've seen so far include:

• replicating the caches to multiple memcache servers
• storing separate caches on each memcache server.

I would also be interested in your experience or thoughts on using moxi with Drupal.

Some relevant discussions I've found so far include

• memcache settings if using memcache 1.5+ (on MySQL performance issue with heavy traffic - help!)
• Multiple web servers and memcache

What I would like to do in this discussion is collect more options, including multiple memcaches with one single apache/php backend.

High performance

I'm interested in finding out how people are configuring Drupal sites to make the best use of multiple memcache servers and distinct machines.

Topologies I've seen so far include:

• replicating the caches to multiple memcache servers
• storing separate caches on each memcache server.

I would also be interested in your experience or thoughts on using moxi with Drupal.

Some relevant discussions I've found so far include

• memcache settings if using memcache 1.5+ (on MySQL performance issue with heavy traffic - help!)
• Multiple web servers and memcache

What I would like to do in this discussion is collect more options, including multiple memcaches with one single apache/php backend.

High performance

Hello,

I would like to seek your advice on what else that I need to do in order to speed up Drupal site. Its really slow for logged in users . The only thing that is good now is Boost , which also has some problems on its own that i worked around.

My site is on a dedicated server on HostGator. Here's what I have so far:

Installed Boost - running ok for anonymous users. Problems with the login block being visible after logging out. I solved this (almost) by ajaxifying the login block (i just wrote my custom code)

Installed AuthCache and XCache - no noticeable speed gains for logged in users . Authcache refuse to cache pages with Views error.

Removed AuthCache, uninstalled XCache.

Installed mod_deflate and APC. Still slow.

As for the database config, i increase the query cache size, hacked views module to include a SQL_CACHE to every SELECT query.

Im running out of tricks so to speak. The site is getting nearly launched and I would really like to make the experience of the logged in users in a acceptable speed.

Here's the server spec:

Intel Xeon 3470+ (Quad Core)
8 GB DDR3 Memory
2 X 500 GB Hard Drives
10 TB Bandwidth
5 Dedicated IPs

Thanks in advance. I hope you can help me.

Ryan

High performance

So we use page level caching on our Pressflow 6 multisite installation and some of the sites use a module for IP based role assignment.

There is an issue with using page caching and IP based role assignment in which a user will get a cached page from Varnish despite having an IP that will give them an authenticated role.

The current solution is to use a Varnish ACL and add the IP addresses to it and have Varnish pass when an IP is found. This causes duplication of IP addresses (in the ACL and Drupal DB), which is not ideal. When the Drupal DB is updated, the ACL needs updated, creating duplicate work.

Does anyone have any advice on determining a solution to this issue?

High performance

HeadFirst are a web development company based in Wellington, New Zealand. We provide enterprise-grade Drupal-based solutions for public sector, corporate and select start-ups. We are looking for a full time Senior Developer/Technical Lead proficient with PHP and Drupal. This is a hands on position - you will be responsible for leading a team of 3-4 developers building Drupal solutions for our clients.

About HeadFirst

We are one of New Zealand's premiere Drupal consulting and development companies. Since 2005 we've been quietly specifying, building and maintaining some of the heaviest trafficked Drupal websites in the country. Our clients are a great mix of government, corporate and start-ups. You will be working out of our light and airy studio in the heart of Wellington's Cuba district.

This is a fantastic opportunity to assume a core position in a friendly team of dedicated and skilled professionals and create high-profile work for a company that rewards initiative and is committed to innovation.

HeadFirst are committed to finding the best fit for our team and welcome qualified international enquiries. If we find you, we are prepared to assist with relocation of an exceptional candidate wishing to experience the great New Zealand lifestyle. You must be eligible to work in New Zealand (hold, or eligible for a NZ citizenship, residency or work permit). All applicants please note this is an office-based role so no telecommuter or remote workers please.

About You

• You write elegant, beautiful, DRY and documented code. You know and apply good software development principles in your everyday work. You use OO design patterns to make your code maintainable and extensible. Your code is your baby.
• You know PHP in and out. You like to use PHP's library of functions to make your life easier and have the PHP manual bookmarked on your browser. Even if you haven't been spending all of your time in PHP, we understand that a good programmer will be a good programmer in any language, so if you are an exceptional programmer, you are welcome to apply.
• You know Drupal well and have created your own modules to create some functionality. You understand the Drupal 6 and 7's hook APIs and drush is your trusty friend.
• You're not afraid of JavaScript, know "the good parts" and are able to create modular, well-written code to manipulate the DOM at your will. You use a framework to make your life easier.
• You are completely at ease in the Linux shell, you can SSH and edit files with your weapon of choice.
• You are part of the Drupal community: If you have created or collaborated on a Drupal contrib module, you will have a big tick in our books. That goes for any other open source projects that you have contributed to. If you have released anything to the community, we want to see it!
• You have a knack for problem-solving and debugging. Bugs can't hide from you because you know how to systematically eliminate pieces of the puzzle until you find the little critter.
• You want to be part of an awesome team of developers. You are a team player; you dislike information hoarders, and you like to teach and learn from your peers.
• You follow technology and web development blogs/podcasts/sites, actively increasing your knowledge of the technologies used on the web. You like to attend conferences and learn new tricks.

Required Technical Skills

• 5+ years of PHP system architecture and development
• 3+ years Drupal (must have D7 experience)
• 3+ years MySQL database integration
• Proven enterprise level Drupal and PHP development experience
• Proven ability to develop new modules & edit existing ones
• Experience integrating third party systems into the Drupal environment
• Experience with JavaScript and frameworks (JQuery preferred)
• Experience with HTML/CSS
• Experience with web services (REST, XML, SOAP)
• Familiarity with version control and version management, preferable Subversion and/or Git
• Experience with Apache configuration and tuning
• Experience with Linux/Unix environment and Linux shell

In addition, demonstrated skills with any of the following will mark you out from the pack:

• Web performance optimisation toolsets (especially Varnish)
• Apache Solr search engine and supporting technologies (Nutch, Tika)
• Linux System Administration Skills
• Ruby: Familiar with language and RoR

Education and Interpersonal Skills

• BS degree or higher, in Computer Science or related field or equivalent experience.
• Excellent interpersonal communication and team interaction skills.
• Strong written and oral communication skills (Fluency in English is critical).
• Strong organizational, and time-management skills.

If this sounds like you email your CV and cover letter to jobs@headfirst.co.nz or post to:

Vacancies
HeadFirst Limited
PO Box 6454,
Wellington 6011
New Zealand

NO agency responses thanks.

Applications close Monday February 6, 2012.

Marketplace

I am going crazy because of this problem ... Become and you get a lot for no reason ...
I have this problem since several months have been circumvented by deleting www .... Noted after several days of normal operation of the website ... But in recent days has become a continuously and, more disturbingly ... when I add new node or edit node ... I normally logged I can add the node and after that I have to log-in again
I have had this problem and prevented me from entering the admin panel until I updated to latest version 6.22 but still happened to me

Regards,

Newspapers on Drupal

Start:  2012-01-26 09:00 - 17:00 America/Los_Angeles User group meeting Organizers:  christefano stevenator

Join us at SANDcamp, the San Diego Drupal Camp, on Thursday, January 26, 2012 for a full day of scalability and performance training! This class is being offered at a 50% discount off our normal prices. Sign up today or contact us with any questions.

    Sign up today at http://www.larks.la/training  

In this all-day workshop, top experts with years of front-line experience building large-scale Drupal deployments show you the best known practices for running fast sites for a large volume of users. Starting with a blank Linux virtual server, we will work through the setup, configuration and tuning of Drupal using Varnish, Pressflow, Apache, MySQL, Memcache and Apache Solr.

Through this process, we will explain common pitfalls and how to avoid them. By the end of this course you should feel comfortable with the basics of how to setup, configure and tune your Drupal site. You’ll learn the most robust solutions the community has discovered.

What you will learn

• How to improve SEO and Google PageRank by increasing site performance
• Pressflow and Drupal performance settings
• Using Content Delivery Networks (CDN)
• Configuring Varnish
• Setting up Opcode caching with APC
• Enabling Memcache(d)
• MySQL configuration and tuning
• Setting up Apache Solr for Search

Prerequisites

• Shell experience (SSH)
• A basic knowledge of networking
• PHP and Drupal development experience
• Knowledge of SQL query syntax

What to bring

Just bring your laptop. We'll provide the servers you'll get to optimize for performance, but you'll need a computer with a web browser as well as a command line client.

Lunch is being handled by the SANDcamp organizers and is an additional $10.

Santa Clarita Valley

Hi,

Found VPS provider for aegir instalation (up to 15 D6-D7 sites, 1/2 of them corporate brochure type), it will be openVZ with guaranteed 2048Mb RAM, mysql+php+apc+apache+smtp, and other basic services, maybe Apache Solr. Memcahed/Nginx/Varnish is a possibility if performance benefits over simple Boost module+APC are worth pain having another service on same vps.

Which linux to choose from this list:

CentOS 4 CentOS 5 CentOS 6 Debian 4 Debian 5 Debian 6 Fedora 14 Fedora 15 openSUSE 11.3 openSUSE 11.4 Ubuntu 10.04 Ubuntu 10.10 Ubuntu 11.04

Should I create poll?

Aegir hosting system