Web Log of Greg Mathews

OK its been about 10 days since my last post so lets try and bring you up to date.

I found that the Yzoo database replication was getting out of sync. I had set up 4 databases all replicating with each other in rotation, ie dbase1 -> dbase2, dbase2->dbase3, dbase3->dbase4 and dbase4->dbase1 then all the scripts would use the database with the lowest server load. In theory it should work, in practice it worked poorly. It appeared the replication itself on such a large database with hundreds of updates every minute was in itself causing a high server load.

I decided to reorganise (again), now dbase1 and dbase2 replicated with each other, and also dbase2 replicated its data to dbase3. I then modified the scripts so all lookups where done on dbase3 only, and any updates where then done on either dbase1 or dbase2 whichever had the lowest load. dbase4 is now used for two other sites listed below.

This appears to have had a dramatic effect, BUT during the process I wiped out the database in my mistake.

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As a perl coder I like to think my  scripts work as described, I do not offer refunds for my scripts unless a bug is discovered at which point I will fix the bug and if requested by the buyer refund them.

A few weeks ago I decided to set up a new website and purchased a script from http://panexis.com/

Unfortunately the script was full of bugs which I listed in an email to the site owner, Anthony Huxtable-Jones, and I asked for a refund. I heard nothing from these people, no  acknowledgement, not a thing.

Eventually I filed a complaint at Paypal, I knew that the fact I purchased digital goods means paypal won’t get involved but I thought it might get a response from Mr  Huxtable-Jones. Well I was right, he did respond saying he had emailed me with installation instructions. Well thats just bull.

Unfortunately the paypal case closed  today and I still have not had a refund.

Now I have to decide what to do and fortunately as he lives in the UK as I do I have a few options:

1. I could forget it, heck $40 ain’t a great amount, but there is the principle.

2. I could take a drive and ask him face to face for my refund, as he obviously has no problem with lying on a Paypal resolution I dare say it would be a waste of time, and cost me more than it’s worth.

3. The third option is to take them to court via the small claims court here in the UK, the cost of this is affordable and if the case is won Mr Huxtable-Jones would be liable for all costs, including interest on the total amount, including the cost of my time, my expenses, the court costs etc so if I win it will end up costing him a lot more than the $40 he stole from me.

I have downloaded the court forms and will complete them this evening. I hate the thought of having to do this but it’s people like this that give other perl sites a bad name.

OK for fun I found humanforsale.com, it is linked to the IQ test site in my last post but hey if anyone wants to buy …

HumanForSale.com - How much are you worth?

I just took a free IQ test, it tries selling you stuff after but was fun.

Free-IQTest.net - What’s your IQ?

OK its been a fun week, server load was still high on the 3 servers I had and I couldn’t pin point the problem so I threw a 4th server at it.

This server was just a NFS server (file server), before this all files where stored on the web server and the database servers connect to that, now with a dedicated nfs server the load should reduce.

Yes it did but  not by enough so I then ordered another web server and 2 database servers. I now have 4 db servers all using replication to keep them in sync and 2 web servers. I was going to use a load balancer but this proved costly after just a short test period so I opted to try a basic Round robin DNS, which although not a true form of load balancing it should work for my needs.

OK things not good, the webservers pick a random database to connect to each time they are accessed, this just does not work. You end up at times with one db server overloading which in turn overloads the web server so I needed an effective means of load balancing the db servers.

I then came up with a small script which runs on one of the web servers. This reads the load of each of  of the db servers and writes the ip address of the db server with the lowest load to a file, each of the scripts on both web servers then ‘requires’ this file so they access the db server with the lowest load.

It’s early days yet but it seems to be working well, the required file is updated a couple of times a minute so the db servers should never end up with a high load and hence the same for the web servers.

In heinsite if I had done this a week ago then I might not have needed the extra servers but its better to have too  much then too little and I do plan to get more traffic so the servers will be utalised.

Happy new year one and all