7.3. Cluster Management Console (CMC)
Cluster Management Console is a web-based tool that you can use to monitor the performance of your cluster. It can also be used to view and modify many of the parameters controlling the function of the cluster. It even allows you to make some changes to the cluster dynamically, while the cluster is running. You can also view the Turbolinux Cluster LoadBalancer 10 documentation through CMC, and submit bug reports.
To run CMC, start a web browser and connect to the appropriate URL. CMC uses the secure HTTP protocol (HTTPS) and runs on port 910. Connecting to CMC requires a web browser that supports SSL. Current versions of Netscape and Internet Explorer will work well.
If you are connecting to CMC using a system that is not a member of the cluster, you can connect using either the address of the cluster itself or the address of an individual ATM. If you use the cluster's virtual IP address, you will end up on the system that is currently the primary ATM. If you are browsing from a system within the cluster, you will have to use the address of an individual ATM. The URL you use to connect to CMC should look something like this:
https://atm1.turbolinux.usa:910
 | If you have trouble connecting to CMC, you may have forgotten the S in https or the port 910 specification. |
The first time you connect to the CMC page, your browser will pop up some dialog boxes showing you the SSL site certificate. This may include a warning that the certificate has not been signed by a certificate authority. You can safely ignore this warning, as you can trust that the information you send will only be seen by your own systems. You may also get a warning that the certificate does not contain the correct site name. This can happen if the ATM has multiple domain names or if you typed incorrect information in when you installed the software. Accept the certificate and follow the prompts that the browser gives you.
Each time you connect to CMC, you will be prompted for a login name and password. You should use the user ID `tlclbadmin'. This account was created when Turbolinux Cluster LoadBalancer 10 was installed. It will initially have the same password as the root account on the ATM to which you are connecting. Type in the password, and you will be connected to CMC. (You can also log in under other user IDs that exist on the ATM, but you will not be able to make any modifications.)
When you first log in, you will be presented with the CMC home page. There are icons along the top that allow you to navigate to various other pages. The icons may vary, depending on what user ID you logged on with.
This page has links to Turbolinux Cluster LoadBalancer 10 documentation as well as the other pages of the CMC administration program. These pages are:
Table 7-1. CMC Home Page
| Home | The Home page has links to man pages and other documentation. The documentation explains how to set up Clustered Mail Server (CMS) using Turbolinux Cluster LoadBalancer 10 and Sendmail with the use of NFS. |
| Status | The Status page is where you can monitor the cluster. It has info on cluster processes, kernel modules, network interfaces, the /proc/net/cluster files, and log files. It also allows you to modify some of the settings and to stop and restart the daemon. |
| Edit | This page lets you view and modify the /etc/clusterserver/clusterserver.conf configuration file. It also allows you to view and modify the /etc/clusterserver/clusterserver.conf configuration file as well as to synchronize content using tlclb_content_sync. |
| Report | The Report page lets you generate an email message containing a large amount of information pertaining to the configuration of your cluster. You can choose who to send the info to and which pieces of information to include. This is useful for reporting bugs to Turbolinux support staff. |
| Licenses | This page is used to view the license files on your system. |
| View | The View page is similar to the Edit page. It shows the configuration file, but does not allow you to edit it. |
If you logged in as `tlclbadmin', you will see all of the pages except for the View page. If logged in as a different user, you will be able to access the View page, but not the Edit, Report, or Licenses pages.
The Status page is where you will spend most of your time in CMC. There are three main sections on the page. The top section shows the output of several utilities: ps, lsmod, and ifconfig. The ps output lets you see whether the Cluster Server daemons are running. The lsmod command lists the kernel modules that have been loaded; the ip_cs module should be listed. The ifconfig program shows the configuration of the network interfaces on the system. You can look through its output to make sure that the proper aliases have been configured. The top section also has buttons that allow you to start and stop the clusterserverd daemon on the active primary ATM.
The next section shows the output of the /proc/net/cluster files. These provide information about the running cluster. The interesting pieces of information are the Statistics and the Connections. These will change as the cluster is accessed. You can use the `Autorefresh' button at the top of the screen to have the information periodically updated. The /proc/net/cluster files will be covered in more detail later in this chapter.
The last section of the Status page displays the output of the three log files used by Turbolinux Cluster LoadBalancer 10. You can look through these logs to determine if there have been any irregularities. However, you do not have access to any of the UNIX filter programs, so you may find it easier to look at the log files from the command line than through the CMC browser interface.
The Edit screen allows you to make modifications to the configuration file. After you have made changes, click on the `Commit' button. This will send the new configuration to all the cluster machines (as long as they are running SSH). If you have not synchronized with any of the servers in the cluster before, you will need to use the form at the bottom to type in the passwords for each server. It is recommended that you use the command-line tlclb_config_sync tool (or run it via turboclusteradmin) before using the CMC synchronization process, so that the system will prompt you for missing passwords instead of requiring you to type them in before running the synchronization process. You can synchronize content from the EDIT page. However, if you are using the Content Synchronization Tool for the first time, you must execute the tool in command-line mode. Execute tlclb_content_sync command or select Content Synchronization Tool in the turboclusteradmin tool. Click the 'Start' button in the 'Synchronize Content' section on the Edit page of CMC. A new browser window will open and show you the status of synchronization.
| Do not hit the browser's `Refresh' or `Reload' button when using CMC. They may re-send button-press events, causing CMC to run the actions associated with those buttons multiple times. |
Another screen called Traffic Monitor is available from the Status page. Traffic Monitor is a Java applet, so your browser must have Java support enabled. The applet shows a graphical representation of the traffic flowing though the ATM. The statistics can be shown by cluster, server, or service.
Here is a view of what Traffic Monitor looks like monitoring several cluster nodes:
