Table Of Contents
The processes running as part of the complete Remote Monitoring solution are indicated in Figure 10-1. Aside from fault-tolerant issues, in theory, all the processes shown in Figure 10-1 can be run on a single machine. However, depending on how many customers and products need to be supported, you may want to divide the work among different machines to optimize performance.
It is difficult to determine hard thresholds for when you might want to use different machines for running Listener, LGMapper and LGArchiver. The answer depends again on the number of customers and products, and on the specifications on the server machines themselves - particularly the amount of physical memory on the machines.
The minimum requirements in Bill Of Materials (BOM) specify a minimum of a 800 MHz processor with 768 MBytes of memory for a Listener machine only, and a 800 MHz processor with 768 MBytes of memory for an LGMapper machine only. These represent minimum requirements and do not address the issue of trying to run Listener, LGMapper and LGArchiver on the same machine.
Figure 10-1 Remote Monitoring Processes
For sites that support less than 25 customers, it should be possible to run all three processes on a single server with 768 MBytes of memory.
For less than 50 customers, it should be possible to run all three processes on a single server with 1 GByte of memory.
For greater than 50 customers, it is recommended that each process run on a separate machine.
For greater than 100 customers, 1 GByte of memory is required for an LGMapper machine. 768 MBytes should still be adequate for the LGArchiver.
The LGMapper machine should be fastest machine with the most amount of memory because it must update the SQL Server database in real time, and it must service potentially tens of AlarmTracker clients in real time as well.
Disk Space Requirements for Alarms Database
It is also difficult to accurately estimate disk space required. This again depends on the number of customers and products supported; and for the Alarms Databases, it also depends on the Alarms Objects History setting in LGMapperCnfg Tool and LGArchiverCnfg Tool.
The BOM specifies a minimum disk size of 18 GBytes for the LGMapper and/or LGArchiver machines.
Use the following formula as a guideline to estimate the SQL Server database MDF file size:
[MDF File Size MBytes] = 0.3 X [Number of Customers] X [Time History in Days]
Monitoring 150 Customers and maintaining a 30-day Alarms Time History results in an MDF file size of on the order of 1.35 GBytes.
Monitoring 30 Customers and maintaining a 60-day Alarms Time History results in an MDF file size of about 540 MBytes.