{"id":471,"date":"2013-07-29T15:09:01","date_gmt":"2013-07-29T20:09:01","guid":{"rendered":"http:\/\/www.poweradmin.com\/blog\/?p=471"},"modified":"2015-04-27T08:45:08","modified_gmt":"2015-04-27T13:45:08","slug":"how-to-monitor-iis","status":"publish","type":"post","link":"https:\/\/www.poweradmin.com\/blog\/how-to-monitor-iis\/","title":{"rendered":"How to Monitor IIS"},"content":{"rendered":"

\"IIS\"<\/a>This will be the first in a series of three blog posts on monitoring. In this article we\u2019ll discuss monitoring Internet Information Services (IIS)<\/strong>, the web hosting platform available in Windows Server editions. IIS is very popular in part because it provides such a compact service with lots of features and configurations. Most enterprises that use Windows Server editions are hosting their websites using IIS. When hosting critical applications, many companies use monitoring software to keep their system administrators informed about the overall behavior of their systems. Such software provides configurable alerts for performance counters, services and applications. We will talk about how to monitor IIS, what the most important performance counters are, and what services should be monitored when talking about Internet Information services.<\/span><\/p>\n

IIS can send information about its application pools and worker processes, active requests, sites and applications, services that depend on it, logging information, abnormal behavior and so on. You should configure your monitoring software<\/a> to measure the amount of CPU and memory percentage that IIS is using. Worker processes are responsible for executing code for web applications, sending and responding to requests and so on. Each worker process should be monitored carefully so that the following parameters are working as desired:<\/span><\/p>\n

Application Pool Name<\/span><\/span><\/h2>\n

Responsible for the worker processes behavior. By default, any app pool will host only one worker process. You should monitor each app pool so that you know exactly what pool is responsible for memory leaking or abnormal CPU usage. Each app pool is identified by its Process ID<\/strong> so you should also take care of monitoring its associated ID.<\/span><\/p>\n

Percent of CPU Usage<\/span><\/span><\/h2>\n

Each worker process reserves a percentage of CPU to execute its active requests. In the field, this counter value is regarded as one of the more important counters to monitor. Poorly written code using too much of the CPU\u2019s resources or bad requests can block applications from using the CPU, which will cause the CPU to run at a very high rate or even at 100% continually. Other counters to monitor include Processor: % Idle Time or Processor: Interrupts\/sec.<\/span><\/p>\n

Disk Space Used by Apps<\/span><\/span><\/h2>\n

This is another important aspect that should be considered when monitoring IIS performance. Any application should have enough space to run in normal parameters. Situations in which disk space is limited or close to 0, can pose a real threat to an application\u2019s performance especially when talking about production environments. Logging too much information can cause log files to grow excessively fast and cause the disk space to be depleted causing poor performance. The overall disk performance may include performance counters like Disk Read Bytes\/sec, Disk Reads\/sec, Disk Write Bytes\/sec or Disk Writes\/sec.<\/span><\/p>\n

Monitoring the Process State is another important item; a process can be in one of three states: starting, running, or stopping. Other applications, viruses and even human interaction may interfere with the normal operation of processes, so you should always check out the state of each one.<\/span><\/p>\n

The amount of memory used by a process should always be monitored carefully. Worker processes must reserve an amount of memory for their normal performance. Here are some memory values to consider:<\/span><\/p>\n

Private Bytes (KB)<\/span><\/span><\/h2>\n

The amount of physical memory used by each process, this value can be seen when opening task manager. A worker process is named W3wp.exe so you should take a look at each one when there is abnormal memory usage. Task manager can indicate several W3wp.exe processes running at the same time so it may be hard to differentiate between them. Remember that the process ID is unique and you can see the requests of each worker process along with its ID from IIS management console.<\/span><\/p>\n

Virtual Bytes (KB)<\/span><\/span><\/h2>\n

The amount of virtual memory that is used by worker processes. This value cannot be seen in task manager but, there are many tools with which you can view the amount of virtual memory consumed by each worker process.<\/span><\/p>\n

Two of the most common counters for Memory are % Committed Bytes in Use and Page Faults\/sec<\/span><\/p>\n

Remember that here are many IIS performance counters that can be monitored. As a system administrator you are able to choose and configure the ones that you desire. Among the performance counters that worth mentioning are:<\/span><\/p>\n