Tag: linkedin

IXP Manager – Planning for v4

A lot has changed in the 3 to 5 years that the decision was made to use certain libraries / technologies / methods on IXP Manager.

In previous major version changes we made some serious architecture changes in one sweep. For example v2 -> v3 saw the complete migration from Doctrine ORM v1 to v2 (which was a change from the Active Record pattern to the Data Mapper pattern).

Today, IXP Manager is a very large project and to do such a sweeping migration in one go would stifle development, break something that isn’t actually broken and take a lot of time.

But, sticking with older technologies and libraries has negative effects also. It creates developer apathy (for which I can personally vouch for). It also provides a major stumbling block for bringing on new developers and contributors (who wants to learn Zend Framework 1 now which has been EOL’d for sometime?).

So, our plan for v4 is to bring in new technologies without throwing away or rewriting everything we have.

IXP Manager is a MVC application that currently uses Doctrine2 as the Model, Smarty as the View and ZF1 as the Controller. Doctrine2 is still current and won’t be changing.

Smarty will remain as the view engine for current / unmigrated functionality. But Smarty is… oh my God… soooooo bad. v4 will default to Twig which is more modern and far better structured from a programming point of view. Coupled with the new framework, it will also allow for a nicer means of skinning. For the interested, Twig has some very nice features including layouts, macros and also some nice security features.

ZF1 has served us well but it’s been EOL’d and is now quite outdated. The new hotness in PHP is Laravel, which I’ve been using to great effect for a while now. Laravel show cases some of the new and best functionality of PHP and using very modern techniques (such as IoC).

But more importantly, Laravel will let us do things in a much different and much more flexible manner for the IXPs using IXP Manager. Some of these include:

  •  Job queues: built-in and simple (to use) support for job queues via Beanstalkd and others. Queuing jobs will provide functionality that we at INEX have been looking for (and it’s also an FAQ from other IXPs) -> reconfiguring services on demand (or, at least quicker than a twice daily cronjob).

Put this together with:

  • Events: Laravel allows us to trigger events and subscribe to them.

A key example of queue and event functionality would be that a change to a VLAN interface (such as checking the route server client box) would trigger a vlan interface changed event. One subscriber to this event would be the route server configuration manager. Based on the VLAN change, this event handler can then queue events. The route servers themselves would monitor these queues and rebuild / reconfigure the route servers appropriately on demand.

Similar handlers for route collectors, DNS ARPA changes, etc. can offer much more real time control of all the services at an IXP.

IoC decouples logic from the controller. What this means is that IXPs who want to do things differently than INEX (let’s say use Cacti instead of MRTG as an example), can swap out MRTG with Cacti with one line of code (that’s assuming we write contracts – interfaces – for such handlers and a Cacti version is coded of course!). But that’s the kind of power and flexibility we’re looking to bring in.

Other features Laravel provides includes:

  • Much improved unit testing on controller actions. Right now, we spin up Apache and MySQL to test controller actions. This is no longer required with Laravel making tests easier to write, more robust and more focused with built in support for mock objects.
  • A much nicer and more structured way of creating command line interfaces rather than the quite clunky way we have of doing it currently.
  • A much more natural way to develop REST API endpoints with json:api compatible responses.

And that leads us to the front end. Right now, the front end and the back end are tightly coupled. During the development lifetime of v4, we want to move more towards an API is Everything back end with a decoupled front end.

This separation will again aid unit testing providing a more reliable and robust IXP Manager. It will allow other IXPs to create their own front end on member facing portals or, even, move to IXP Manager as their back end system but retaining investment of current member portals by adding new features from IXP Manager through API endpoints. It will also allow existing systems in IXPs to integrate with IXP Manager to provision services and ports for example.

One of the bigger tests of this plan will be the (long awaited and badly needed) revamp of the member facing area. We’re currently planning the UI / UX of this to deliver key information to members in the best way possible. This will include Bootstrap v3 which is fluid from the ground up so mobile browsers to wide screen browsers should be supported naturally.

During the early stages of v4, we’ll create the API endpoints necessary to support the member portal functions and then create a front end on that using Ember.js.

Other changes in v4 will include:

  • A switch from package management via Git sub-modules to composer and Packagist as is current standard practice.
  • Introduction of Bower for front end asset management.
  • And we’ll need a task runner for pulling everything together – for that we’ll use Grunt (although that’ll mostly be a development / release prep tool rather than an end user requirement).

So, that’s what we’re looking at! It won’t happen overnight but we’ll continue our policy of release early, release often and we’ll update the documentation and provide complete upgrade instructions at the appropriate times. Some of the above is also subject to change depending on practical experience / issues as we move towards it.

Comments, ideas, etc. are all welcome.

Irish Radio Stations on Linux (2013)

This is updating an older article from October 2010. While Linux has come a long way since then for playing back various types of media (and new services such as tunein make it easier again), I still like to just play the radio from the command line.

The following are updating working aliases:

alias newstalk='cvlc http://newstalk.fmstreams.com:8008/listen.pls'
alias rteradio1='cvlc http://av.rasset.ie/av/live/radio/radio1.m3u'
alias rteradio1extra='cvlc http://av.rasset.ie/av/live/radio/radio1extra.m3u'
alias 2fm='cvlc http://av.rasset.ie/av/live/radio/2fm.m3u'
alias todayfm='cvlc http://audiostore.todayfm.com/audio/todayfmIRL_64K.asx'

Synchronising Microsoft Exchange to Another IMAP Server

This post is much less of a detailed how-to but rather some useful links. We were tasked with the job of sync’ing about 1,000 MS Exchange mailboxes to a Dovecot server. This needed to be done via an administrator account on the Exchange end as individual user passwords were not available.

The tool of choice for this is imapsync.  Unfortunately, there is not a single formula that will work for all as it can depend on the Exchange configuration and version as well as the use of domains on the Exchange and ActiveDirectory servers.

To help understand the various combinations of logins for Exchange, I found the following invaluable: Understanding login strings with POP3/IMAP.

Also invaluable is the imapsync FAQ – just search for mentions of Exchange.

In the end, the following worked for me (but your mileage will most definitely vary!):

./imapsync --host1 exchange-server 
    --user1 'domain/adminuser/user' --password1 'admin-password' 
    --authmech1 LOGIN 
    --host2 dovecot-server --user2 user@example.com 
    --password2 userpassword

One key element here is that when logging into Exchange as an individual user I had to use --authmech1 NTLM but if you use this auth method with the above user string, you will always end up logging into the admin’s mailbox, not the user’s. That, at least, was my experience.

MySQL 5.6 – Memcached / NoSQL Support and More

MySQL 5.6 has been released with some interesting new features and performance increases:

  • What’s New in MySQL 5.6
  • DBA and Developer Guide to MySQL 5.6
  • InnoDB Integration with memcached:MySQL 5.6 includes a NoSQL interface, using an integrated memcached daemon that can automatically store data and retrieve it from InnoDB tables, turning the MySQL server into a fast “key-value store” for single-row insert, update, or delete operations. You can still also access the same tables through SQL for convenience, complex queries, bulk operations, application compatibility, and other strengths of traditional database software.

    With this NoSQL interface, you use the familiar memcached API to speed up database operations, letting InnoDB handle memory caching using its buffer pool mechanism. Data modified through memcached operations such as ADD, SET, INCR are stored to disk, using the familiar InnoDB mechanisms such as change buffering, the doublewrite buffer, and crash recovery. The combination of memcached simplicity and InnoDB durability provides users with the best of both worlds.

  • Multi-threaded Slaves
  • Improved IPv6 Support – both in the bind to address option and the INET_ATON() function.
  • Replication improvements.

All in all, some nice new features. Especially the memcached integration.

That said, MariaDB seems to be making inroads on MySQL with some distributions considering a switch. Some interesting reading from that project includes:

Woot! We hit 50Gbps at INEX!

 

Adventures with LDAP (OpenLDAP) – SSL, Multi-Master Replication and Monitoring

In my career to date, I successfully managed to avoid all but the periphery engagement in OpenLDAP. Until recently that is – we had to build a Microsoft Exchange like environment with open source software in a way that was closely integrated and easily managed. But, more on that another time. For anyone else diving into OpenLDAP, here are some articles on my experiences that I have penned:

Nagios Plugin for Checking Backups via rsnapshot

We’ve just added a check_rsnapshot.php script to our nagios-plugins bundle on Github. This script will verify rsnapshot backups via Nagios using a number of checks / tests:

  • minfiles – checks the number of files in a snapshot against a minimum expected number;
  • minsize – checks the size of a snapshot against a minimum expected size;
  • log – parses the rsnapshot log to ensure the most recent runs for each retention period completed successfully;
  • timestamp – checks for files created server side containing a timestamp and thus ensuring snapshots are succeeding;
  • rotation – checks that retention directories are being rotated; and
  • dir-creation – checks that retention directories are being created.

Please see this Github wiki page for more information including instructions.

Analysing MySQL Slow Query Logs

MySQL has a really useful feature that allows it to log slow queries where slow is a minimum time defined by you in micro seconds. It helps a lot is diagnosing website outages or slow responsiveness issues after the fact.

Unfortunately I couldn’t find any nice graphical tools for analysing these but there are a few command line tools:

mysqldumpslow

MySQL’s own tool, mysqldumpslow, which aggregates queries and allows you to sort them by: query time or average query time; lock time or average lock time; rows sent or average rows sent; or the number of queries.

Percona’s MySQL Slow Query Log Analyser

Dating from 2006, Percona’s Peter Zaitsev wrote about their own version of a slow query log analyser (local copy) which has given me good results. Note that their micro time patch has since been incorporated into MySQL mainstream.

One of the main differences over MySQL’s own version is that as well as printing the aggregated query (with number and string literals wildcarded), it also prints a real example of the query allowing a copy and paste to MySQL for execution with EXPLAIN.

Example output with query details redacted:

### 230 Queries 
### Total time: 4708.948293, Average time: 20.4736882304348
### Taking 0.093420 to 203.693466 seconds to complete
### Rows analyzed 0 - 141008
SET timestamp=XXX;
SELECT ... FROM ... AS A 
        INNER JOIN ... AS C ON C.item_id = A.item_id 
    WHERE XXX AND C.item_lang = 'XXX' AND ... 
    ORDER BY CATALOG.item_sort LIMIT XXX;

SET timestamp=1348032761;
SELECT ... FROM ... AS A 
        INNER JOIN ... AS C ON C.item_id = A.item_id 
    WHERE 1 AND C.item_lang = '1' AND ... 
    ORDER BY C.item_sort LIMIT 1;

 

So it’s finally happened…

RIPE put out a press release today:

RIPE NCC Begins to Allocate IPv4 Address Space From the Last /8

14 Sep 2012

On Friday 14 September, 2012, the RIPE NCC, the Regional Internet Registry (RIR) for Europe, the Middle East and parts of Central Asia, distributed the last blocks of IPv4 address space from the available pool.

This means that we are now distributing IPv4 address space to Local Internet Registries (LIRs) from the last /8 according tosection 5.6 of “IPv4 Address Allocation and Assignment Policies for the RIPE NCC Service Region“.

This section states that an LIR may receive one /22 allocation (1,024 IPv4 addresses), even if they can justify a larger allocation. This /22 allocation will only be made to LIRs if they have already received an IPv6 allocation from an upstream LIR or the RIPE NCC. No new IPv4 Provider Independent (PI) space will be assigned.

It is now imperative that all stakeholders deploy IPv6 on their networks to ensure the continuity of their online operations and the future growth of the Internet.

In other words, for all intents and purposes, Europe (and Central Asia and the Middle East) is out of IPv4 addresses. Funnily enough, I’m actually happy that this long predicted day has arrived and we can start the next phase of IPv6 deployment.

Thunderbird 15 Released with Chat – But Shite Error Handling

I’ve just moved a couple of my chat and IRC accounts over to Thunderbird 15 to see how they look. After all, one communications application is better than three. Mozilla have a good instruction set here and they work well for standard chat accounts.

However, most corporations using in house XMPP servers with self signed certificates and these fail with no error messages whatsoever. It was by fluke I found this post: How to Make Thunderbird Chat Work with Most XMPP/Jabber Accounts. Thanks for doing the legwork Rod, this helped a lot.