Step by Step Trouble Shooting"
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'''2. Is it a static resource?''' | '''2. Is it a static resource?''' | ||
| − | YES (js, css, images...) → check [[#ZK Server Configuration]] → STILL SLOW → [[#Network Issue]] | + | YES (js, css, images...) → check [[#ZK Server Configuration ]] (debug / cache / compression) → STILL SLOW → [[#Network Issue]] |
NO (dynamic request into ZK application) | NO (dynamic request into ZK application) | ||
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'''RECEIVING''' | '''RECEIVING''' | ||
:'''3.d) Is the response unreasonably big?''' | :'''3.d) Is the response unreasonably big?''' | ||
| − | :YES → | + | :YES → [[#ZK Server Configuration ]] (render on demand / compression) |
:NO | :NO | ||
:↓ | :↓ | ||
Revision as of 11:39, 17 September 2013
Performance SOP
Identify the Bottleneck
Usually the bottleneck can be found in one of these areas:
- client
- network
- server
To breakdown a slow performing web application is a good idea to start, where the bad performance is perceived... in the browser. Most modern browsers provide very sophisticated tools to start the search for the bottleneck and draw some conclusions, and exclude other possible causes easily.
- Dev tools (Network)
- Chrome -> [F12]
- Firefox -> [F12] or Firebug
- IE9+ -> [F12]
- IE8 -> fiddler2
File:Chrome developer tools network.jpg
Investigating the network traffic following the questions below the biggest problem area(s) should become apparent after a few minutes:
1. Are there one or more long running requests?
NO → #Client Side Issue
YES
↓
2. Is it a static resource?
YES (js, css, images...) → check #ZK Server Configuration (debug / cache / compression) → STILL SLOW → #Network Issue
NO (dynamic request into ZK application)
- *.zul = full page request (can be followed by ajax requests)
- zkau/* = ajax request
↓
3. Which PHASE of the request is slowest ? (examples based on Chrome developer tools)
File:Chrome developer tools network example phases.jpg
CONNECTING (or one of Proxy, DNS Lookup, Blocking, SSL)
- 3.a) Is this a network problem (everything between browser and ZK Application)?
- test ping / trace route to different servers
- test dns lookup timing
- YES → #Network Issue
- NO → #Server Side Issue (application takes long time to accept connection, or even times out)
SENDING
- 3.b) Is the request unreasonably big?
- YES → #Client Side Issue
- NO
- ↓
- 3.c) Is the bandwidth low?
- e.g. try upload the same amount of data to the server via ftp/scp to check possible upload speed
- YES → #Network Issue
- NO → #Server Side Issue (application server receiving request data slowly)
WAITING → #Server Side Issue (application server taking long time to prepare response)
RECEIVING
- 3.d) Is the response unreasonably big?
- YES → #ZK Server Configuration (render on demand / compression)
- NO
- ↓
- 3.e) Is the bandwidth low?
- e.g.try to download the same amount of data from the server via ftp/scp to check download speed
- YES → ask your administrator to fix it ;)
- NO → #Server Side Issue (appserver sending response data slowly)
Server Side Issue
Server Side Profiling
Memory Issue
ZK Server Configuration
- check debug mode → zk config should not be enabled (disabled by default)
- check caching config → should not be disabled (enabled by default)
- http://books.zkoss.org/wiki/ZK_Configuration_Reference/zk.xml/The_Library_Properties/org.zkoss.web.classWebResource.cache
- http://books.zkoss.org/wiki/ZK_Configuration_Reference/zk.xml/The_Library_Properties/org.zkoss.zk.WPD.cache
- http://books.zkoss.org/wiki/ZK_Configuration_Reference/zk.xml/The_Library_Properties/org.zkoss.zk.WCS.cache
- check compression settings → should not be disabled (enabled by default)
- check render on demand settings
- http://books.zkoss.org/wiki/ZK_Developer%27s_Reference/Performance_Tips/Client_Render_on_Demand
- TODO more ROD settings, fetch size...
- TODO ??? maybe more tweaks ???
Client Side Issue
Client Side Profiling
Memory Issue
Network Issue
If something in your infrastrucure (routers, proxies, web servers...) is causing the performance issues, there is little you can do as web application developer. So these topics are not part of this SOP
→ Please ask your network administrator to identify/exclude infrastructure problems.