• Contents
  • 1 About the chapters of this manual
  • 2 An introduction to HELIOS WebShare
  • 3 Installation
  • 4 Administration
  • 5 HELIOS Admin
  • 6 Using WebShare
  • 7 WebShare Web Server
  • 8 WebShare File Server
  • 9 HELIOS Document Hub
  • 10 WebShare security
  • A Special characters in file names
  • B WOStarter – Web service health check
  • C Technical notes
• <
• B WOStarter – Web service health check
• >

B WOStarter – Web service health check

All HELIOS services are monitored by the HELIOS Service Controller. If a program aborts due to a major problem, the Service Controller will log errors and restart the service. The “wostarter.so” (WOStarter) is a plug-in for the Service Controller to constantly monitor its whole web service. If a web service gets stuck and is not responding correctly to HTTP requests from the WOStarter, the Service Controller will restart the service. This adds an additional level of availability auditing to the Service Controller.

The file “wostarter.so” is located in “HELIOSDIR/lib”. The HELIOS Service Controller can use this plug-in to start/stop and monitor the WebShare Web Server (“websharewoa”). It can be activated for the WebShare Web Server via the following preference:

# prefvalue -k 'Services/websharewoa/ServiceStarter' -t str
  "de.helios.servicestarter.wostarter"

WOStarter periodically checks whether the “websharewoa” service is still alive. WOStarter can detect the following web service failures:

• HTTP response does not contain an expected keyword

• HTTP response contains a keyword that is not expected

• HTTP error occurs

• HTTP response is incomplete

• No HTTP response at all

When WOStarter detects a problem with its monitored web service, it will log detailed errors and restart the web service. Custom WOStarter settings can be configured via preferences.

Examples:

 

The WatchdogInterval preference specifies the timeout in seconds (default=600):

# prefvalue -k 'Programs/websharewoa/WatchdogInterval' -t int [value]

The WOHost preference specifies the hostname or the IP address of the web service (default=localhost):

# prefvalue -k 'Programs/websharewoa/WOHost' -t str [value]

The WOPort preference specifies the port of the web service (default=2009):

# prefvalue -k 'Programs/websharewoa/WOPort' -t int [value]

The ResponsePositive preference specifies optional strings that must be contained in the HTTP response (no default).

# prefvalue -k 'Programs/websharewoa/ResponsePositive' -t strlist [value]

The ResponseNegative preference specifies optional strings that must be contained in the HTTP response and which indicate an error (no default).

# prefvalue -k 'Programs/websharewoa/ResponseNegative' -t strlist [value]