1. PhysicalDisk / % Idle Time – should not be less than 60%. Preferably staying at the top of your chart at all time.
2. PhysicalDisk / Avg. Disk sec/read – should not be higher than 20ms.
3. PhysicalDisk / Avg. Disk sec/write – should not be higher than 20ms.
Both (2) and (3) are the ones in Performance Monitor to measure the IO latency. The higher number usually indicating a problem that is hard disk related, either a program that constantly accessing the disk more often than usual, or a hard disk is failing
4. PhysicalDisk / Current Disk Read or Write Queue Length – should not be higher than 2.
Hard page faults occur when the page is not located in physical memory or a memory-mapped file created by the process (the situation we discussed above). The performance of applications will suffer when there is insufficient RAM and excessive hard page faults occur
a soft page fault occurs when the page is resident elsewhere in memory.
Memory counters :
=================
5. Memory / Available MBytes – minimum 10% of memory should be free and available. Less than that usually indicating there is insufficient memory which can increase paging activity. You should consider adding more RAM if that happens.
6. Memory / Pages/sec – should not be higher than 1000. A number higher than that, as a result of excessive paging, usually indicates there may be a memory leak happening.
7. Memory / Cache Bytes – indicates the amount of memory being used for the file system cache. There may be a disk bottleneck if this value is greater than 300MB.
Network :-
==========
8. Network Interface / Bytes Total/sec – measures the rate at which bytes are sent and received over each network adapter.
healthy – less than 40% of the interface consumed
caution – 41% – 60%
critical – 61% – 100%
9. Network Interface / Output Queue Length – measures the length of the output packet queue in packets.
healthy – 0
caution – 1-2
critical – >2
Paging File counters :
======================
Paging is the process of moving pages from the RAM to Hard Disk.
to know the shortage of memory you can look at the frequency of Paging.
Page Fault. A page fault occurs when a program attempts to access a block of memory that is not stored in the physical memory, or RAM. The fault notifies the operating system that it must locate the data in virtual memory, then transfer it from the storage device, such as an HDD or SSD, to the system RAM.
The performance of applications will suffer when there is insufficient RAM and excessive hard page faults occur
Hard page faults occur when the page is not located in physical memory or a memory-mapped file created by the process
soft page fault occurs when the page is resident elsewhere in memory.
10. Paging File / % Usage – should not be greater than 10%.
Pages/sec : High Pages/sec values can indicate insufficient RAM memory
Process (_Total) \ Private Bytes : A consistently increasing value may be indicative of a memory leak
Memory \ Pool Paged Bytes ;- Paged Pool is a larger resource than Nonpaged pool - however, if this value is consistently greater than 70% of the maximum configured pool size, you may be at risk of a Paged Pool depletion
Memory \ Committed Bytes ; if the value is constantly increasing without leveling off, you should investigate
Memory \ Available Bytes :If this value falls below 5% of installed RAM on a consistent basis, then you should investigate. If the value drops below 1% of installed RAM on a consistent basis, there is a definite problem!
Memory \ %Committed Bytes in Use ;- If this value is consistently over 80% then your page file may be too small
PROCESSOR QUEUE LENGTH : Threads in the processor queue are ready to run but can’t, due to another thread running on the processor. Queues with sustained element counts greater than 2 are indicative of a bottleneck.
AVAILABLEMBYTES :
Committed Bytes :
Process Count The number of processes in the computer.
Thread count The number of threads in the computer.
% Interrupt Time % time the processor spends receiving and servicing hardware interrupts.
%Privileged Time % time that the process threads spent executing code in privileged mode.
% Processor Time % time that the processor spends to execute a non-Idle thread.
% User Time % time the processor spends in the user mode.
Disk Free %Disk free space percent.
Disk Free Space Disk free space.
Disk Reads/sec The rate of read operations on the disk.
Disk Writes/sec The rate of write operations on the disk.
Disk Read Bytes/sec The rate at which bytes are transferred from the disk during read operations.
Disk Write Bytes/sec The rate at which bytes are transferred to the disk during write operations.
Disk Transfers/sec The rate of read and write operations on the disk.
Memory
=======
Free Memory Amount of free memory.
Page Faults/sec The average number of pages faulted per second. This counter includes both hard faults (those that require disk access) and soft faults (where the faulted page is found elsewhere in physical memory.)
Page Reads/sec The rate at which the disk was read to resolve hard page faults.
Page Writes/sec The rate at which pages are written to disk to free up space in physical memory.
Pages Output/sec The rate at which pages are written to disk to free up space in physical memory.
Pool Nonpaged Bytes The size, in bytes, of the nonpaged pool, an area of system memory (physical memory used by the operating system) for objects that cannot be written to disk, but must remain in physical memory as long as they are allocated.
Pool Paged Bytes The size, in bytes, of the paged pool, an area of system memory (physical memory used by the operating system) for objects that can be written to disk when they are not being used.
Network
Output Queue Length The length of the output packet queue
Packets Outbound Errors The number of outbound packets that could not be transmitted because of errors.
Packets Received Errors The number of inbound packets that contained errors preventing them from being deliverable to a higher-layer protocol.
Kilobytes Received/sec The rate at which kilobytes are received on the network interface.
Kilobytes Sent/sec The rate at which kilobytes are sent on the network interface.
Idle Workers :
==============
The number of idle workers can tell you if you’re short of resources or if you have them in abundance. A lack of idle workers means that there are too many requests coming in and your server will have to create new threads and processes to handle them. This could cause each request to take more time to process, which increases the latency of each request. If you’re facing this issue, you should consider increasing the resource allocation to your Apache web server.
On the other hand, if there’s always a large number of idle workers, you have allocated too many resources. You might as well use those resources for other services running on the same machine.
In either case, your decision completely depends on the amount of traffic you are getting on your web server and the amount of resources you have on your machines. Before making any changes to your resources, it’s best to observe the idle worker count over a few weeks. This will eliminate the possibility of having low traffic in an off-season.
===================
1. Web Server:
A web server delivers content or services to end users over the internet. It translates the web URL path to the system resource and responds with the requested system resource. i.e. it accepts the HTTP requests from the clients (via web browsers) and serves it if the requests are pertaining to the static contents (like images or HTML document). The basic performance metrics include:
Server Throughput
Requests per second
CPU usage
Memory Usage
Disk Usage
2. Application Server:
App server provides the business logic of the web application. The client requests (via web browser) pertaining to the dynamic contents (like JSP page which needs to render and fetch data from the database server). The key performance metrics include:
% Processor Time
Page Faults per second
Avg. Disk Queue Length
Pages per second
Requests per second
CPU usage
Memory Usage
3. Database Server:
It is a data storage and retrieval system which manages the data queries. It provides data to the application server when requested. The key performance metrics include:
Query response times
CPU utilization
Memory utilization
Raw Data :-
===========
Raw Data will contain the all the details with error meesages , vuser id details and complete end to end performance test details which we conduct for our applications , but it is useful to track any issues in vuserid level or error messages for identifying the issue in application. So mostly Raw Data which is heavy stored details for debugging the application level errors can be used on the situation basis but regularly we wont bother about this Raw Data.
Generally for any performance test or load test in Perfroamance center there is any option to collate the results , before collating the results it will show the Raw results which is not analyzed properly for loading the complete deatils .
So if we collate the results properly then it will show the Analyzed Results which contains all the Graphs and detailed summary report for the corresponding performance test which has conducted. So it is always good practice to share the Analyzed results across the project teams.
No comments:
Post a Comment