Evaluating Memory and Cache Usage

After you have observed memory usage under normal conditions and established your memory baseline, you might notice that the memory counters sometimes stray from the typical range. The following sections describe how to investigate conditions that cause memory values to deviate from the baseline.

The following activities help you to learn about and analyze memory usage and memory bottlenecks by using System Monitor counters and other tools:

  • Investigating memory shortages

  • Investigating disk paging

  • Investigating user-mode memory leaks

  • Investigating kernel-mode memory leaks

  • Monitoring the cache

  • Resolving memory and cache bottlenecks

Table 28.1 summarizes the most important counters to monitor for analyzing memory usage.

Table 28.1 Counters for Analyzing Memory Usage

To monitor for

Use this Object \ Counter

Memory shortages

Memory\Available Bytes Process ( All_processes )\Working SetMemory\Pages/secMemory\Cache Bytes

Frequent hard page faults

Memory\Pages/secProcess ( All_processes )\Working Set Memory\Pages Input/sec Memory\Pages Output/sec

Excess paging with a disk bottleneck

Memory\Page Reads/secPhysical Disk\Avg. Disk Bytes/Read

Paging file fragmentation

PhysicalDisk\Split IOs\secPhysicalDisk\% Disk Read TimePhysicalDisk\Current Disk Queue LengthProcess\Handle Count

Memory leaks; memory-intensive applications

Memory\Pool Nonpaged AllocationsMemory\Pool Nonpaged BytesMemory\Pool Paged BytesProcess( process_name) \Pool Nonpaged BytesProcess( process_name )\Handle CountProcess( process_name )\Pool Paged BytesProcess( process_name )\Virtual BytesProcess( process_name )\Private Bytes

Cache Manager efficiency

Cache\Copy Read Hits %Cache\Copy Reads/secCache\Data Map Hits %Cache\Data Maps/secCache\MDL Read Hits %Cache\MDL Reads/secCache\Pin Read Hits %Cache\Pin Reads/secTo identify cache bottlenecks, also use Memory\Pages Input/sec with these counters.

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Important

The LogicalDisk object counters are not available by default. If you want to monitor the values for these counters, you must first activate the counters by typing diskperf  – yv at the Windows command prompt.