[CONF] Apache Sling > Higher level observation services

[confluence]

Higher level observation services Page edited by Bertrand Delacretaz Changes (10) {style} .deflist h4 { margin-top: 0; font-size:100%; font-weight:normal; font-style:italic; } .deflist h4 + p { margin-top: 0; } .deflist p { margin-left: 2em; } .deflist ul, .deflist ol { margin-left: 2em } {style} Analyzing how we use observation in our Sling-based apps shows a number of recurring patterns, described in this page. ... h2. Cached Content {div:class=deflist} h4. Trigger Changes in content under specific paths (or path regexps), with optional restrictions on node types and/or event types. h4. Action Clear an internal cache that is rebuilt the next time someone needs it. h4. Typical uses Configurations, CSS/_javascript_ processing, Sling installer, etc. h4. Frequency Content changes are usually not very frequent, for the above typical uses. h4. Performance Some latency between content changes and processing is usually not a problem. h4. Potential issues N requests coming just after clearing the cache should cause just one cache rebuild, not N. {div} h2. Content Ingestion {div:class=deflist} h4. Trigger Changes in content under specific paths (or path regexps), with optional restrictions on node types and/or event types. h4. Action Clear an internal cache that is rebuilt the next time someone needs it. h4. Typical uses Configurations, CSS/_javascript_ processing, Sling installer, etc. h4. Frequency Content changes are usually not very frequent, for the above typical uses. h4. Performance Some latency between content changes and processing is usually not a problem. h4. Potential issues N requests coming just after clearing the cache should cause just one cache rebuild, not N. {div} h2. Content Export {div:class=deflist} h4. Trigger Changes in content under specific paths (or path regexps), with optional restrictions on node types and/or event types. h4. Action Clear an internal cache that is rebuilt the next time someone needs it. h4. Typical uses Configurations, CSS/_javascript_ processing, Sling installer, etc. h4. Frequency Content changes are usually not very frequent, for the above typical uses. h4. Performance Some latency between content changes and processing is usually not a problem. h4. Potential issues N requests coming just after clearing the cache should cause just one cache rebuild, not N. {div} h2. Aggregation of changes {div:class=deflist} h4. Trigger Changes in content under specific paths (or path regexps), with optional restrictions on node types and/or event types. h4. Action Clear an internal cache that is rebuilt the next time someone needs it. h4. Typical uses Configurations, CSS/_javascript_ processing, Sling installer, etc. h4. Frequency Content changes are usually not very frequent, for the above typical uses. h4. Performance Some latency between content changes and processing is usually not a problem. h4. Potential issues N requests coming just after clearing the cache should cause just one cache rebuild, not N. {div} h2. Consistency Checks and Fixes {div:class=deflist} h4. Trigger Changes in content under specific paths (or path regexps), with optional restrictions on node types and/or event types. h4. Action Clear an internal cache that is rebuilt the next time someone needs it. h4. Typical uses Configurations, CSS/_javascript_ processing, Sling installer, etc. h4. Frequency Content changes are usually not very frequent, for the above typical uses. h4. Performance Some latency between content changes and processing is usually not a problem. h4. Potential issues N requests coming just after clearing the cache should cause just one cache rebuild, not N. {div} h2. Content Replication {div:class=deflist} h4. Trigger Changes in content under specific paths (or path regexps), with optional restrictions on node types and/or event types. h4. Action Clear an internal cache that is rebuilt the next time someone needs it. h4. Typical uses Configurations, CSS/_javascript_ processing, Sling installer, etc. h4. Frequency Content changes are usually not very frequent, for the above typical uses. h4. Performance Some latency between content changes and processing is usually not a problem. h4. Potential issues N requests coming just after clearing the cache should cause just one cache rebuild, not N. {div} h2. Message Queue {div:class=deflist} h4. Trigger Changes in content under specific paths (or path regexps), with optional restrictions on node types and/or event types. h4. Action Clear an internal cache that is rebuilt the next time someone needs it. h4. Typical uses Configurations, CSS/_javascript_ processing, Sling installer, etc. h4. Frequency Content changes are usually not very frequent, for the above typical uses. h4. Performance Some latency between content changes and processing is usually not a problem. h4. Potential issues N requests coming just after clearing the cache should cause just one cache rebuild, not N. {div} h2. Workflow/Job Trigger {div:class=deflist} h4. Trigger Changes in content under specific paths (or path regexps), with optional restrictions on node types and/or event types. h4. Action Clear an internal cache that is rebuilt the next time someone needs it. h4. Typical uses Configurations, CSS/_javascript_ processing, Sling installer, etc. h4. Frequency Content changes are usually not very frequent, for the above typical uses. h4. Performance Some latency between content changes and processing is usually not a problem. h4. Potential issues N requests coming just after clearing the cache should cause just one cache rebuild, not N. {div} Full Content Analyzing how we use observation in our Sling-based apps shows a number of recurring patterns, described in this page. Using JCR observation directly or Sling OSGi events does not make a big difference in the final results, but the implementations are very different. The commit hooks provided by http://jackrabbit.apache.org/oak/ provide yet another way of observing content changes, which might be more efficient or scalable in some cases. Being able to express these common observation patterns as higher-level services, if we can do that, would allow for switching the underlying implementation seamlessly, and would also help promote best practices in how we use events, by minimizing the amount of code to write at the application level. Observation usage patterns Let's list the frequent patterns that we see w.r.t observing changes in content. Cached Content Trigger Changes in content under specific paths (or path regexps), with optional restrictions on node types and/or event types. Action Clear an internal cache that is rebuilt the next time someone needs it. Typical uses Configurations, CSS/_javascript_ processing, Sling installer, etc. Frequency Content changes are usually not very frequent, for the above typical uses. Performance Some latency between content changes and processing is usually not a problem. Potential issues N requests coming just after clearing the cache should cause just one cache rebuild, not N. Content Ingestion Trigger Changes in content under specific paths (or path regexps), with optional restrictions on node types and/or event types. Action Clear an internal cache that is rebuilt the next time someone needs it. Typical uses Configurations, CSS/_javascript_ processing, Sling installer, etc. Frequency Content changes are usually not very frequent, for the above typical uses. Performance Some latency between content changes and processing is usually not a problem. Potential issues N requests coming just after clearing the cache should cause just one cache rebuild, not N. Content Export Trigger Changes in content under specific paths (or path regexps), with optional restrictions on node types and/or event types. Action Clear an internal cache that is rebuilt the next time someone needs it. Typical uses Configurations, CSS/_javascript_ processing, Sling installer, etc. Frequency Content changes are usually not very frequent, for the above typical uses. Performance Some latency between content changes and processing is usually not a problem. Potential issues N requests coming just after clearing the cache should cause just one cache rebuild, not N. Aggregation of changes Trigger Changes in content under specific paths (or path regexps), with optional restrictions on node types and/or event types. Action Clear an internal cache that is rebuilt the next time someone needs it. Typical uses Configurations, CSS/_javascript_ processing, Sling installer, etc. Frequency Content changes are usually not very frequent, for the above typical uses. Performance Some latency between content changes and processing is usually not a problem. Potential issues N requests coming just after clearing the cache should cause just one cache rebuild, not N. Consistency Checks and Fixes Trigger Changes in content under specific paths (or path regexps), with optional restrictions on node types and/or event types. Action Clear an internal cache that is rebuilt the next time someone needs it. Typical uses Configurations, CSS/_javascript_ processing, Sling installer, etc. Frequency Content changes are usually not very frequent, for the above typical uses. Performance Some latency between content changes and processing is usually not a problem. Potential issues N requests coming just after clearing the cache should cause just one cache rebuild, not N. Content Replication Trigger Changes in content under specific paths (or path regexps), with optional restrictions on node types and/or event types. Action Clear an internal cache that is rebuilt the next time someone needs it. Typical uses Configurations, CSS/_javascript_ processing, Sling installer, etc. Frequency Content changes are usually not very frequent, for the above typical uses. Performance Some latency between content changes and processing is usually not a problem. Potential issues N requests coming just after clearing the cache should cause just one cache rebuild, not N. Message Queue Trigger Changes in content under specific paths (or path regexps), with optional restrictions on node types and/or event types. Action Clear an internal cache that is rebuilt the next time someone needs it. Typical uses Configurations, CSS/_javascript_ processing, Sling installer, etc. Frequency Content changes are usually not very frequent, for the above typical uses. Performance Some latency between content changes and processing is usually not a problem. Potential issues N requests coming just after clearing the cache should cause just one cache rebuild, not N. Workflow/Job Trigger Trigger Changes in content under specific paths (or path regexps), with optional restrictions on node types and/or event types. Action Clear an internal cache that is rebuilt the next time someone needs it. Typical uses Configurations, CSS/_javascript_ processing, Sling installer, etc. Frequency Content changes are usually not very frequent, for the above typical uses. Performance Some latency between content changes and processing is usually not a problem. Potential issues N requests coming just after clearing the cache should cause just one cache rebuild, not N. Change Notification Preferences View Online | View Changes | Add Comment