Troubleshooting web performance

Been working on a tricky problem which shows how you have to be methodical to try and find the problem

Our helpdesk database was running very slow

so i upgraded the instance ram – this made loading pages faster but seem to make any writes to the mysql db slower!

Now this is a lightly loaded server so should be lightening fast

I looked at the apache logs – nothing obvious but a couple of errors

I upgraded the system to the latest version – this enabled me to spot the first problem

Schema updates had not been applied – this is fairly painless – take a back up and run

rt-setup-database-4 –action upgrade

This boosted the load times but still did little for the saving

after trailing round the RT forums it occurred to me that there must be a simple solution

I disabled various ad-ons – no real change

Then i realised the problem was SENDING emails – the way its setup it waits for sendmail to send the message BEFORE loading the next webpage

So why was it taking so long to load?

In the end it was our old friend DNS – removed the dead dns server  from resolv.conf (which was obviously timing out) and much much faster

With hindsight – it was taking a little while to ssh to the server – this was caused by the same problem, but wasn’t really  a problem.

So next time i get slow ssh’s into a server i will remember – check your dns setup!

I could change the configuration to not wait for sendmail to finish  – but lets see how it goes…

 

 

 

 

Handy Geek Links with instuctions

Troubleshooting DNS:

kloth.net

Troubleshooting the misbehaving website:

rexswain.com http viewer

Troubleshoot MX records:

mxtoolbox.com

Track down the random ISP .txt records or the exchange server that will not work remotely….

Microsoft Remote Connectivity Analyzer

https://testconnectivity.microsoft.com

IF all else fails … did you check the hosts file??

 

Article #20: vmware hp P2V fix

A classic problem i get asked about a lot: HP Teaming refuses to die!

Basics

Class: Solutions
fixing the network teaming

Content

Description Freefield: Using HP Proliant Support Pack Cleaner v1.1 from

https://www.ctxadmtools.com/DownloadTool.aspx?ProdID=86

reboot

done

Article #5: Fujutsu Megaraid HDD upgrade

Basics

Class: Solutions
Adding disks to Fujitsu servers

Content

Description Freefield: Fujitsu Disk upgrades with LSI megaraid

After much experimentation the solution I found to do this

Add the additional hard disks on spare sata ports
Boot into the raid configuration and create a new array with the two hard disks
The ui here sucks – you need to press spacebar/enter to select each disk press f10 to create the array – ignore that it says that it will add them to the existing array when you press f10 again it does create a new array make sure to select raid 1 (The default) and ensure you have added both disks
There is no need to initialise the array – if you make a mistake you can delete the new array safely and try again
On reboot boot of an up to date version of acronis to copy the drives and resize
Power off – remove the old disks

Power on – tell megaraid to ignore the drive changes

Exchange 2003 pop connector missing email

Check pop3 connector running in services

iisreset at command line

move  good email from C:\Program Files\Microsoft Windows Small Business Server\Networking\POP3\Failed Mail

to the above “Incoming mail” directory

wait for pop3 polling (15mins)

Check with user all ok

I enable IT managers to go from crisis management to business development

old ssl certificate is still being given out by IIS

netsh http show sslcert
This showed me two SSL Certificate bindings. One on IP:Port 0.0.0.0:443 with the correct certificate and one on IP:Port :::443 with an expired certificate. I opened CertMgr.msc for the Local Computer (see here for instructions) and searched for the invalid certificate and discovered it had expired.

To resolve the issue I did the following

netsh http delete sslcert ipport=:::443
iisreset /restart