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Posted to commits@felix.apache.org by gh...@apache.org on 2020/04/08 09:21:19 UTC
[felix-dev] branch master updated (f51a4a8 -> d6f2e22)
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ghenzler pushed a change to branch master
in repository https://gitbox.apache.org/repos/asf/felix-dev.git.
from f51a4a8 Merge pull request #12 from apache/feature/FELIX-6245-condition-service-interfaces-FELIX-6250-healthcheck-monitor
new 51a3fd6 FELIX-6250 Use semantically correct event topic with 'component'
new d6f2e22 FELIX-6250 Documentation for Health Check Monitor
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Summary of changes:
healthcheck/README.md | 52 ++++++++++++++++++++++
.../hc/core/impl/monitor/HealthCheckMonitor.java | 6 +--
.../core/impl/monitor/HealthCheckMonitorTest.java | 4 +-
3 files changed, 57 insertions(+), 5 deletions(-)
[felix-dev] 02/02: FELIX-6250 Documentation for Health Check Monitor
Posted by gh...@apache.org.
This is an automated email from the ASF dual-hosted git repository.
ghenzler pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/felix-dev.git
commit d6f2e223316c5591d92d82f02b60b820183420be
Author: georg.henzler <ge...@netcentric.biz>
AuthorDate: Wed Apr 8 11:15:05 2020 +0200
FELIX-6250 Documentation for Health Check Monitor
---
healthcheck/README.md | 52 +++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 52 insertions(+)
diff --git a/healthcheck/README.md b/healthcheck/README.md
index 24c0b18..ac5695b 100644
--- a/healthcheck/README.md
+++ b/healthcheck/README.md
@@ -257,6 +257,58 @@ based on their tags (positive and negative selection, see the `HealthCheckFilter
The DEBUG logs of health checks can optionally be displayed, and an option allows for showing only health checks that have a non-OK status.
+## Monitoring Health Checks
+
+### Setting up a monitor configuration
+
+By default, health checks are only executed if explicitly triggered via one of the mechanisms as described in [Executing Health Checks](#executing-health-checks) (servlet, web console plugin, JMX, executor API). With the `HealthCheckMonitor`, Health checks can be regularly monitored by configuring the the **factory PID** `org.apache.felix.hc.core.impl.monitor.HealthCheckMonitor` with the following properties:
+
+Property | Type | Default | Description
+----------- | -------- | ------ | ------------
+`tags` and/or `names` | String[] | none, at least one of the two is required | **Will regularly call all given tags and/or names**. All given tags/names are executed in parallel. If the set of tags/names include some checks multiple times it does not matter, the `HealthCheckExecutor` will always ensure checks are executed once at a time only.
+`intervalInSec` or `cronExpression` | Long or String (cron) | none, one of the two is required | The interval in which the given tags/names will be executed
+`registerHealthyMarkerService` | boolean | true | For the case a given tag/name is healthy, will register a service `org.apache.felix.hc.api.condition.Healthy` with property tag=<tagname> (or name=<hc.name>) that other services can depend on. For the special case of the tag `systemready`, the marker service `org.apache.felix.hc.api.condition.SystemReady` is registered
+`registerUnhealthyMarkerService` | boolean | false | For the case a given tag/name is **un**healthy, will register a service `org.apache.felix.hc.api.condition.Unhealthy` with property tag=<tagname> (or name=<hc.name>) that other services can depend on
+`treatWarnAsHealthy` | boolean | true | `WARN` usually means [the system is usable](#semantic-meaning-of-health-check-results), hence WARN is treated as healthy by default. When set to false `WARN` is treated as `Unhealthy`
+`sendEvents` | boolean | false | Whether to send events for health check status changes. See [below](#osgi-events-for-health-check-status-changes) for details.
+
+### Marker Service to depend on a health status in SCR Components
+
+It is possible to use OSGi service references to depend on the health status of a certain
+tag or name. For that to work, a `HealthCheckMonitor` needs to be configured for the relevant tag or name. To depend on a health status in a component, use a `@Reference` to one of the marker services `Healthy`, `Unhealthy` and `SystemReady` - this will then automatically activate/deactivate the component based on the certain health status. To activate a component only upon healthiness of a certain tag/name use the following code:
+
+```
+ @Reference(target="(tag=dbavail)")
+ Healthy healthy;
+
+ @Reference(target="(name=My Health Check)")
+ Healthy healthy;
+```
+For the special tag `systemready`, there is a convenience marker interface available:
+
+```
+ @Reference
+ SystemReady systemReady;
+```
+It is also possible to depend on a unhealthy state (e.g. for fallback functionality or self-healing):
+
+```
+ @Reference(target="(tag=dbavail)")
+ Unhealthy unhealthy;
+```
+
+NOTE: This does not support the [RFC 242 Condition Service](https://github.com/osgi/design/blob/master/rfcs/rfc0242/rfc-0242-Condition-Service.pdf) yet - however once final the marker services will also be able to implement the `Condition` interface.
+
+### OSGi events for Health Check status changes
+
+For tags/names that a `HealthCheckMonitor` is configured for and `sendEvents` is set to true, events are sent whenever a result status for any of the given tags/names has changed. The events are sent for the topic `org/apache/felix/healthchange/*`. The following events are sent:
+
+Topic Prefix | Example | Description
+------ | ------- | -----
+`org/apache/felix/healthchange/tag/` | `org/apache/felix/healthchange/tag/mytag` | Sent whenever the aggregate status for any of the tags as configured in `HealthCheckMonitor` changed
+`org/apache/felix/healthchange/name/` | `org/apache/felix/healthchange/tag/My_Tag_Name ` (spaces are replaced with underscores to ensure valid topic names) | Sent whenever the status for any of the names as configured in `HealthCheckMonitor` changed
+`org/apache/felix/healthchange/component/` | `org/apache/felix/healthchange/component/com/mycomp/myproj/MyHealthCheck` (`.` are replaced with slashes to produce valid topic names) | Sent for health checks that are based on SCR components (in addition to the name event)
+
## Servlet Filters
### Service Unavailable Filter
[felix-dev] 01/02: FELIX-6250 Use semantically correct event topic
with 'component'
Posted by gh...@apache.org.
This is an automated email from the ASF dual-hosted git repository.
ghenzler pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/felix-dev.git
commit 51a3fd62fb9ee635d557984e3479dc590921886c
Author: georg.henzler <ge...@netcentric.biz>
AuthorDate: Wed Apr 8 11:14:21 2020 +0200
FELIX-6250 Use semantically correct event topic with 'component'
instead of 'class' (it's only the class by default but can be any name)
---
.../org/apache/felix/hc/core/impl/monitor/HealthCheckMonitor.java | 6 +++---
.../apache/felix/hc/core/impl/monitor/HealthCheckMonitorTest.java | 4 ++--
2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/healthcheck/core/src/main/java/org/apache/felix/hc/core/impl/monitor/HealthCheckMonitor.java b/healthcheck/core/src/main/java/org/apache/felix/hc/core/impl/monitor/HealthCheckMonitor.java
index 81a3e96..f687d68 100644
--- a/healthcheck/core/src/main/java/org/apache/felix/hc/core/impl/monitor/HealthCheckMonitor.java
+++ b/healthcheck/core/src/main/java/org/apache/felix/hc/core/impl/monitor/HealthCheckMonitor.java
@@ -341,10 +341,10 @@ public class HealthCheckMonitor implements Runnable {
LOG.debug("HealthCheckMonitor: Posted event for topic '{}': Status change from {} to {}", topic,
previousStatus, status);
if (!(executionResult instanceof CombinedExecutionResult)) {
- String componentClass = (String) executionResult.getHealthCheckMetadata().getServiceReference()
+ String componentName = (String) executionResult.getHealthCheckMetadata().getServiceReference()
.getProperty(ComponentConstants.COMPONENT_NAME);
- if (StringUtils.isNotBlank(componentClass)) {
- String topicClass = EVENT_TOPIC_PREFIX + "/class/" + componentClass.replace(".", "/");
+ if (StringUtils.isNotBlank(componentName)) {
+ String topicClass = EVENT_TOPIC_PREFIX + "/component/" + componentName.replace(".", "/");
eventAdmin.postEvent(new Event(topicClass, properties));
LOG.debug("HealthCheckMonitor: Posted event for topic '{}': Status change from {} to {}",
topicClass, previousStatus, status);
diff --git a/healthcheck/core/src/test/java/org/apache/felix/hc/core/impl/monitor/HealthCheckMonitorTest.java b/healthcheck/core/src/test/java/org/apache/felix/hc/core/impl/monitor/HealthCheckMonitorTest.java
index 70c3cd4..dfc770f 100644
--- a/healthcheck/core/src/test/java/org/apache/felix/hc/core/impl/monitor/HealthCheckMonitorTest.java
+++ b/healthcheck/core/src/test/java/org/apache/felix/hc/core/impl/monitor/HealthCheckMonitorTest.java
@@ -204,7 +204,7 @@ public class HealthCheckMonitorTest {
assertEquals(2, postedEvents.size());
assertEquals("org/apache/felix/healthchange/tag/test-tag", postedEvents.get(0).getTopic());
assertEquals(Result.Status.OK, postedEvents.get(0).getProperty(HealthCheckMonitor.EVENT_PROP_STATUS));
- assertEquals("org/apache/felix/healthchange/class/org/apache/felix/TestHealthCheck", postedEvents.get(1).getTopic());
+ assertEquals("org/apache/felix/healthchange/component/org/apache/felix/TestHealthCheck", postedEvents.get(1).getTopic());
reset(eventAdmin);
// without status change
@@ -222,7 +222,7 @@ public class HealthCheckMonitorTest {
assertEquals("org/apache/felix/healthchange/tag/test-tag", postedEvents.get(0).getTopic());
assertEquals(Result.Status.CRITICAL, postedEvents.get(0).getProperty(HealthCheckMonitor.EVENT_PROP_STATUS));
assertEquals(Result.Status.OK, postedEvents.get(0).getProperty(HealthCheckMonitor.EVENT_PROP_PREVIOUS_STATUS));
- assertEquals("org/apache/felix/healthchange/class/org/apache/felix/TestHealthCheck", postedEvents.get(1).getTopic());
+ assertEquals("org/apache/felix/healthchange/component/org/apache/felix/TestHealthCheck", postedEvents.get(1).getTopic());
reset(eventAdmin);
// without status change