[SLING-3747] Provide a way to signal Jcr Installer to pause and resume scanning

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: JCR Installer 3.1.8
• Component/s: Installer
• Assignee: Chetan Mehrotra
• Reporter: Chetan Mehrotra
• Created: 08/Jul/14 11:09
• Updated: 04/Jun/20 15:16
• Resolved: 11/Aug/14 11:24

Description

Currently Sling Installer JCR Provider would listen for observation event and would perform a rescan every 500 msec upon receiving any observation event.

This at times cause issue when large number of bundles get updated in repository say via installation of bug fixing content package. Further if same content package also updates the repository bundle then it causes issues as repository bundle might get updated midway while content package is still being deployed

Based on fmeschbe suggestion this can be done via introducing a signalling mechanism between component which installs package and JCR Installer. It would work something like this

1. JCR Installer would check if there is any node under /system/sling/installer/jcr/pauseInstallation as a signal to pause installation.
2. Package installer would create a child node under the above path before installing the package and remove it post installation

This should also address the issue in cluster deployment

Issue Links

• is related to: SLING-9502 Document pitfalls of the installer-provider-installhook
• is related to: SLING-8293 Pause the JCR Installer while package is being installed
• relates to: SLING-5421 Allow JCR installer to recover from being paused indefinitely