Performance Tree performance-tree

Last update: Mon Jan 08 2024 00:00:00 GMT+0000 (Coordinated Universal Time)

Scope scope

The following diagram is meant to provide guidance on the steps to take to troubleshoot performance issues. It is split in five sections for easier reading.

Each step in the diagram is linked to a documentation resource or a recommendation.

Prerequisites and Assumptions prerequisites-and-assumptions

The assumption is that a performance issue is observed on a given page (either an AEM console or a web page) and can be reproduced consistently. Having a way to test or monitor the performance is a pre-requisite before starting the investigation.

The analysis starts at step 0. The goal is to determine which entity (Dispatcher, external host, or AEM) is responsible for the performance issue then determine which area (server or network) should be investigated.

Section 1 section

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Section 2 section-1

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Section 3 section-2

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Section 4 section-3

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Section 5 section-4

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Reference Links reference-links

Step

Title

Resources

Step 0

Analyze Request Flow

You can use standard HTTP request analysis in the browser to analyze the request flow. For more info on how to do this analysis on Chrome, see:

https://developer.chrome.com/docs/devtools/

Step 2

Are requests coming from external hosts?

You can use standard HTTP request analysis in the browser to analyze the request flow. See the above links on how to do this analysis on Chrome.

Step 3

Can the requests be cached?

For more information on cacheable requests and general Dispatcher performance optimization advice, see Dispatcher Performance Optimization.

Step 4

Are requests coming from the Dispatcher?

To see if the requests are cached properly, check the Dispatcher debugging documentation.

Step 5

Is the Dispatcher trying to authenticate each request via AEM?

Check if the Dispatcher sends HEAD requests to AEM for authentication before delivering the cached resource. Look for HEAD requests in the AEM access.log. For more information, see Logging.

Step 6

Is the geographic location of the Dispatcher far away from the users?

Move the Dispatcher closer to the users.

Step 7

Is the network layer of the Dispatcher OK?

Investigate the network layer for saturation and latency issues.

Step 8

Is the slowness reproducible with a local instance?

Use Tough Day to replicate "real-world" conditions from the production instances. If this scenario is not realistic for the space of your development, make sure to test the production instance (or an identical staging one) in a different network context.

Step 9

Is the geographical location of the server far away from the users?

Move the server closer to the users.

Steps 10 and 29

Investigate network layer

Investigate the network layer for saturation and latency issues.

For the author tier, it is recommended that the latency does not surpass 100 milliseconds.

For more information on performance optimization tips, see this page.

Step 11

Move server closer or add one per region

Step 12

Troubleshoot AEM server

Check the following sub steps in the diagram for more information.

Step 13

Check hardware requirements

Check the documentation on Hardware Sizing Guidelines.

Step 14

Check for frequent causes of performance issues

Step 15

Find slow requests

You can check for slow requests by analyzing the request.log or by using rlog.jar.

For more information about using rlog.jar, see this page.

See Find requests with long duration times using rlog.jar.

Step 16

Profile server

For information about profiling tools you can use with AEM, see Tools for Monitoring and Analyzing Performance.

Step 17

Find slow methods in profiling

Step 18

Common scenarios of profiling

See Analyzing Specific Scenarios in the Performance Optimization section.

Step 19

100% CPU

https://experienceleague.adobe.com/docs/experience-manager-release-information/aem-release-updates/previous-updates/aem-previous-versions.html

Step 20

Out of memory

Step 21

Disk I/O

See the Disk I/O section in the Monitoring and Maintaining documentation.

Steps 22 and 22.1

Cache ratio

See Calculating the Dispatcher Cache Ratio.

Step 23

Slow queries

Best Practices for Queries and Indexing

Step 24

Repository tuning

Step 25

Workflows running

Step 26

MSM Infrastructure

Multisite Manager Best Practices

Step 27

Assets tuning

Step 28

Unclosed sessions

Checking for unclosed JCR sessions

Step 30

Move Dispatcher closer (add one per "region"?)

Step 31

Use CDN in front of Dispatcher

Using Dispatcher with a CDN

Step 32

To offload the AEM server, use session management at the Dispatcher level

Enabling Secure Sessions

Step 33

Make requests cacheable

How to improve cache ratio; make requests cache-able (Dispatcher best practices)

Also, consider the below settings to optimize your caching configurations

Set a no-cache rule for HTTP request that is not GET
Configure query strings to not be cacheable
Do not cache URLs with missing extensions
Cache authentication headers (possible since Dispatcher version 4.1.10)

Step 34

Upgrade Dispatcher version

You can download the latest Dispatcher version at this location:

Follow link

Step 35

Configure Dispatcher

Configuring the Dispatcher

Step 36

Check cache invalidation

Steps 37 and 38

Lazy-loading

See the Gem Session on AEM Web Performance.

Step 39

Use pre-connect to reduce connection overhead

See the Gem Session above. Also, additional pre-connect documentation on W3c: https://html.spec.whatwg.org/#linkTypes

Steps 40 and 41

External hosts latency and response time

Investigate the latency and response time for the external hosts.

Steps 45
and 47

Using HTTP/2

See the Gem Session for steps 37,38 and 39. Also, check out this forum post on HTTP/2 support.

Step 49

Shrink payload size

Enable Gzip and shrink the image size.

Steps 42 and 43

Keep-Alive

Is the Keep-Alive header present in the different requests to reuse connections? Otherwise, it would mean that each request leads to another connection establishment, which introduces unnecessary overhead. (Standard HTTP request analysis in the browser)

You can check the Proxy Server tool to check for Keep-Alive connections.

Step 44

How many requests are made?

Perform standard HTTP request analysis in the browser.

Step 46

Reduce number of requests

Concatenate resources (images, CSS sprites, JSON)
Clientlibs embedding:
1. Creating Client Library Folders - see heading Using embedding to minimize requests

Step 48

What is the size of the payload?

Standard HTTP request analysis in the browser

Steps 50 and 51

JS code blocking

https://experienceleague.adobe.com/docs/experience-manager-gems-events/gems/gems2016/aem-web-performance.html

recommendation-more-help

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