Determining Hardware Requirements
Before beginning this project, you will need to make sure your hardware meets the requirements for the expected user load. Most of your hardware-related decision making will be based on total process count. First, you should check your operating system documentation for suggested hardware configurations based on this total process count. In particular, pay attention to requirements for CPU, memory, and swap space. In addition to these operating system requirements, Caché specifically requires shared memory to store various system structures such as global, routine, and network buffers.
See your platform’s version of the Caché Installation Guide for an understanding of how Caché uses memory, and how to calculate the appropriate memory configuration.
In some cases, you may be changing hardware platforms as part of the migration process. Your Caché migration is a good opportunity to move to a more powerful hardware platform, as Caché makes optimal use of SMP and multiple-disk configurations. In these cases, you will need to carefully consider how your application will exist in the new hardware configuration.
For the most recent list of currently supported Caché platforms, see the Current and Planned Caché Products page on the InterSystems web site:
Determining Networking Requirements
Caché 5 networking supports the following message format protocols:
Enterprise Cache Protocol (ECP)
Distributed Cache Protocol (DCP)
Distributed Data Processing (DDP)
DTM-NetBIOS (For a DTM client/Caché server configuration only)
on top of one of these communication protocols:
TCP/IP (both UDP and TCP)
You use the Management Portal to set up your network connections; see the Caché System Administration Guide. For more information on Caché’s supported network protocols, see the Distributed Data Management Guide.
Mixed MSM/Caché Networks
Peer-to-peer networking between MSM and Caché can be achieved using DDP over Raw Ethernet. With this method, MSM can act as either a client or a server to Caché. At some stages of the conversion process, you may find it useful to have some machines running MSM and some running Caché, with Caché-level networking connecting your systems.
When planning a mixed network, bear in mind the following limitations:
MSM does not support DCP or ECP networking.
Caché does not support the Open MUMPS Interconnect (OMI) protocol.
You cannot share routines across a network between Caché and MSM
Caché does not support RVGs (Remote Volume Groups). For Caché to Caché connectivity it is recommended that you use ECP, which can be likened to a high-performance equivalent to MSM’s RVGs.
You cannot share string collated globals over a DDP network between MSM and Caché (see the section on “Preserving MSM String Collation” for details).
Accessing 8KB databases over DDP may cause problems because DDP does not support accessing globals that contain nodes with subscripts containing more than 255 characters.
Running Caché and MSM on the Same Machine
It is possible to have Caché and MSM installed and running on the same machine. If you plan on using DDP networking between Caché and MSM on the same machine, you will need two separate Ethernet cards (see “Configuring Multiple Caché Instances” in the Caché System Administration Guide).
If you want both Caché and MSM to run connectivity services simultaneously on Windows NT, you will need to do the following:
For Telnet, change the Telnet port number for one of the systems. By default, both Caché and MSM use port 23.
For LAT services, make sure that both Caché and MSM use unique service names.
For Serial Port services, make sure MSM and Caché use unique ranges of COM ports.
For more information on Telnet, LAT, and Serial Port services, see “Terminal Servers”.
Ensuring Unique $JOB Values Across the Network
While MSM networking could be set up to ensure unique $JOB values across a network, Caché cannot. Since Caché obtains a process ID (PID) from the operating system for each Caché process, it’s possible for client processes from different machines to carry the same $JOB value. If your application sets globals indexed by $JOB from multiple clients to the same server, you can correct the situation with any of the following options:
Combine $ZU(110), which returns the Caché node a process is running on, with $JOB to guarantee a unique identifier. This is functionally similar to MSM’s $SYS.
Store any globals indexed by $JOB locally on each client (this is generally a good practice on any system).
Use subscript-level global mapping to distribute the global differently.
The steps taken to install Caché depend upon the host operating system. The following outline will highlight some important information, but you should read your platform’s version of the Caché Installation Guide for more details.
Before installing Caché make sure you that you have the following:
System privileges for your machine (either Administrator, root, or system, depending on your operating system)
Approximately 200MB of free hard disk space for the core product installation
TCP/IP configured for your OS (Caché requires that you have the TCP/IP protocol installed on your machine, even for stand-alone configurations, because it is used to connect the Caché GUI utilities to the server.)
The license key supplied to you by InterSystems to activate Caché’s product features (recommended)
Installing the Caché License Key
If you have not configured your Caché license during initial installation of the product, or you can do so with the Management Portal, or via a host-based editor such as vi, emacs, or edit. The license information is stored in an ASCII file called cache.key, found in your Caché manager’s directory. Caché license keys are case-sensitive. If the license is not properly entered, Caché will start in a single-user mode. All fields must be entered.
On Windows platforms, the installation program will ask you for your license key during installation if it has not already located one. In UNIX®, if the installation program does not prompt you for the license, you will need to enter the license manually, using either a host-based editor or the License wizard on a PC client running Caché. In either case, the information must be entered exactly as shown on your paper copy of the license.
If you purchased licenses for multiserver systems, you must also configure one or more license managers to allocate the Caché license units authorized by the key.
Unlike MSM, where licenses are purchased in blocks of concurrent users, Caché licenses are typically purchased on a simple per concurrent user basis. For example, you could purchase a 17 user Caché license, which is not possible under MSM. There are a number of different license types available with Caché, and it is recommended that you contact your InterSystems Account Manager for more detailed information on this topic.
For more information on how to install and configure your license, see your platform’s version of the Caché Installation Guide.