Stewart Robinson's questions

The F5 GTMs automatically reroute users to one of the available datacenters should one fail. How does it do this? For instance the F5 could act as a DNS server and simply serve a different IP to clients but how would it get around caching?

I'm interested in this because I'd like to see whether obtaining this sort of availability is possible with open source tools that could be coded to do similar stuff

I have a four server cluster with Oracle Clusterware managing 4 MySQL instances on them. On failure Clusterware will move the MySQL instance to another server.

I am on Proliant servers and also have ASR running. Recently I had a failover where ASR hard rebooted a server and Clusterware had to step in to bring up the database on another server.

I'm quite open to disabling ASR if necessary.

What production configurations should I run with ASR and Clusterware?

I need to host stuff for a financial institution on EC2. The bank wants complete Two Factor Authentication so Stuff like having SSH with a key with password. Something like SecureID or similar would be great. How can I effectively create two factor authentication across SSH to my EC2 environment?

Also could I consider OpenVPN as part of the Two Factor encyption?

I'm testing a flash app and need to log every HTTP post request it makes so I need to be able. My default setting is to use squid. What can I do?

I know how to audit which user accesses a file. How can I tell which process is modifying files in a directory?

We use nagios to monitor our network. Has anyone found a sample map file containing entries that correspond to the services in nsclient++

What is the optimal time between running DeleteExpiredSessions. I've just inherited a database for a 3M monthly unique session web app and the DeleteExpiredSessions runs every minute. This seems like massive over kill to me. Opinions?

I want to be able to give read only access to my SQL Server 2008 database server. In particular two databases one called "live" and one called "stage".

Essentially the guys who receive this username and password should be able to select from any of the tables, but not perform any update, delete or inserts. Of course they shouldn't be able to perform DDL operations. I could probably get away with banning them from running stored procs if I had to.

Any advice?

My Website is hosted across 3 production web servers and uses ASPNET Session management in the db. I have no sticky sessions on the load balancer so every other request goes around the servers in round robin.

Because of this I can't see a problem with allowing the app pool to use more than one worker.

What do I need to check first? Or should I just move forward?

I want to make sure that my Sql Server 2008 box doesn't degrade over time as I develop my application. What are the best 5 counters to keep track of?

I have a table that has fairly heavy queries. The column I am joining on is an FK to a PK in another table. This column seems to take up of the query time with a table scan which leads me to believe that SQL Server won't be able to use the index on the remote table and will need it's own index on my source table.

I am fairly sure I am right but it would be great if a SQL Server 2008 genius could wade in on this.

I am looking for hosting, ec2 is SAS 70 compliant (almost) and I would have gone straight for PCI compliant and tier 4 only but I'm considering SAS 70. What are the differences or similarities?

In my specific example I am trying to use OpenVPN and need to port forward 1194 to my internal ubuntu machine on 192.168.1.12 from the Orange Livebox, but the port forwarding page wants an external IP address to enter on the port forwarding page whereas I want to allow all IPs to contact 1194 on that machine.

Any ideas?

I don't really want to put the machine in the DMZ as it runs all sorts of other stuff that I don't want public

I guess this question could be entitiled, how do CDN's work at the DNS level but the real problem I have is that my company has datacenters in three continents and we have to have europe.example.com us.example.com and asia.example.com

CDN's typically send you to the local datacenter I imagine depending on your IP address. This must be a DNS thing where you have the DNS server in USA send you to a USA datacenter for the same example.com DNS lookup?

Am I wrong? If I am wrong about this, how would I do this effectively and if possible without central (non DNS) servers?

I looked at Tools for load-testing HTTP servers? but I couldn't see how to replay my own existing logs in any of those tools. I have a bug that only occurs under certain load operations which my existing JMeter and AB testing stuff can't reproduce.

I want to simply give the tool access_logs and have it play them back, either faster or at the same speed.

I've found MySQL fairly slow on EC2 and I am sure it is disk speed. My EC2 install is a test environment so I don't need to keep the data if a block should fail which I think allows me to use XFS.

So....What is the fastest filesystem to use under Linux on EC2 for MySQL?

EDIT: I am using EBS, also I am looking to see if anyone has experience outside of EXT3 as that is what I already find slow

I was resetting permissions on /var/www and screwed it up!

Now I get frequent problems connecting to mysql, using the package manager because /var has fairly open permissions.

Anyone know if /var is a fairly blanket

sudo chmod -R 700 *

Help!

Is it possible to use both the OpenVPN and DynDNS services together? Would you advised against it for any reason (security, performance, etc.)?

I am using DynDNS for my dynamic IP. Will OpenVPN work with a dynamic IP?

I use subversion and don't want to check out over 1 GB of images onto each developers desktop so how can I just have one central image server and have apache push 404's just from *.jpg for example to this other server