Clearspace runs best on recommended hardware and environmental configurations. Use this document as a starting place for estimating what you'll need to support your deployment.
Note: Also, note that at this time Clearspace is not supported in a virtualized environment. A virtualized environment can slow the application's performance by severely decreasing disk I/O and network I/O under load.
For internal deployments, expect a higher ratio of actions that write to the database. This includes creating new content, adding comments and replies, updating content, and so on. Here, writes are estimated as 15 percent of the number of page views.
| Page Views per Month | Database Writes per Month | CPUs | RAM | Location of App Server and Database |
Clustered? |
|---|---|---|---|---|---|
| 500,000 | 75,000 | 1 dual core CPU (at least 2 GHz) | 2GB, 1GB Java heap | Share a box | No |
| 1,000,000 | 150,000 | 1 dual core CPU (at least 2 GHz) | 2GB, 1GB Java heap | Separate boxes | No |
| 5,000,000 | 750,000 | 1 dual core CPU (at least 2 GHz) | 4GB, 2GB Java heap | Separate boxes | Yes |
| 10,000,000 | 1,500,000 | 1 dual core CPUs (at least 2 GHz) | 4GB, 2GB Java heap | Separate boxes | Yes |
| 25,000,000 | 3,750,000 | 2 dual core CPUs (at least 2 GHz) | 4GB, 2GB Java heap | Separate boxes. Database box is a quad core. | Yes |
In general, and external deployment is going to have a very high ratio of page views relative to database writes. That's because external deployments tend to support communities with a large number of people who rarely contribute but often check back to read what others are posting.
| Page Views per Month | Content Created per Month | CPUs | RAM | Location of App Server and Database |
Clustered? |
|---|---|---|---|---|---|
| 500,000 | 20,000 | 1 dual core CPU (at least 2 GHz) | 2GB, 1GB Java heap | Share a box | No |
| 1,000,000 | 20,000 | 1 dual core CPU (at least 2 GHz) | 2GB, 1GB Java heap | Separate boxes | No |
| 5,000,000 | 50,000 | 1 dual core CPU (at least 2 GHz) | 4GB, 2GB Java heap | Separate boxes | Yes |
| 10,000,000 | 50,000 | 1 dual core CPUs (at least 2 GHz) | 4GB, 2GB Java heap | Separate boxes | Yes |
| 25,000,000 | 100,000 | 2 dual core CPUs (at least 2 GHz) | 4GB, 2GB Java heap | Separate boxes/DB box is a quad core | Yes |
It's important to use the latest JVM (Java Virtual Machine) for your platform as well as the correct GC (garbage collection) settings. Clearspace requires at least a 1.5 VM; 1.6 is recommended.
| Heap | Startup Parameters |
|---|---|
| 1 GB | -Xms512m -Xmx1024m -XX:MaxPermSize=256m -XX:+UseParNewGC -XX:+UseConcMarkSweepGC |
| 2 GB | -Xms512m -Xmx2048m -XX:MaxPermSize=256m -XX:+UseParNewGC -XX:+UseConcMarkSweepGC |
In both cases this will allocate a 512 MB heap at minimum as well as allocate 256 MB to the "PermGen" space of the VM heap. Note that you might want to increase the MaxPermGen size to 512 MB if any of the following are true for your instance:
Finally, we configure the "Concurrent Mark Sweep" GC algorithm. We've found this to be the optimal GC setting for deployments on multiple core processor configurations.
If you want to debug the contents of your VM, use the following extra startup parameters:
| Debug Parameters |
|---|
| -verbose:gc -XX:+PrintGC -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -Xloggc:/path/to/log/file/here.log |
Please refer to your application server's documentation for information on setting these startup parameters.
For clustered configurations, it is absolutely essential that all cluster nodes have system time with as little drift as possible. This is generally adjusted on a regular interval by syncing with an NTP server inside the firewall. For servers under higher load, it may be necessary to increase the clock sync interval as loaded servers will be more likely to experience clock drift.
It's important to keep your network as simple as possible to minimize environmental interference. For example, a bad network architecture would contain multiple firewalls, proxies and network hops between your users, the application server and the database. Keep the following things in mind:
