[KARAF-6386] Race condition in initialization of Activators (Port already in use: 1099)

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.3.0, 4.2.7
• Component/s: karaf
• Assignee: Jean-Baptiste Onofré
• Reporter: Xtra Coder
• Created: 22/Aug/19 09:01
• Updated: 27/Nov/19 15:03
• Resolved: 02/Sep/19 09:10

Description

Recently I came across the problem mentioned in KARAF-5054 (at startup - Port already in use: 1099 - whereas another port is specified in configuration)

After digging through debugger - I see this is indeed a "race condition" issue - Activator's doStart() in one thread happens before "CM Configuration Updater" thread reaches to the same activator and provides appropriate properties. And it may affect other activators.

The bug as i see it - SomeActivator.doStart() do not ensure startup configuration is loaded before start, however all need environment is already available. I've fixed this for myself in the following way. Please apply to sources if it seems appropriate:

1. Add this method into org/apache/karaf/util/tracker/BaseActivator.java

    protected boolean ensureStartupConfiguration(String configId) throws IOException {
        if (this.configuration != null) {
            return true;
        }

        ConfigurationAdmin configurationAdmin = getTrackedService(ConfigurationAdmin.class);
        if (configurationAdmin != null) {
            Configuration configuration = configurationAdmin.getConfiguration(configId);
            Dictionary<String, Object> properties = (configuration == null) ? null : configuration.getProperties();

            if (properties != null) {
                this.configuration = properties;
                return true;
            }
        }

        // Since logging may not get initialized - let's spam directly to console
        System.out.println("No startup configuration for: " + configId);

        return false;
    }

2. Add following initialization line ... 

    protected void doStart() throws Exception {
        // Verify dependencies
        ConfigurationAdmin configurationAdmin = ...

        if (!ensureStartupConfiguration("org.apache.karaf.management")) {
            return;
        }

... into affected activators. Here is the list I've got in my environment:

org.apache.karaf.jaas.modules.impl.Activator - CM Configuration Updater (ManagedService Update: pid=[org.apache.karaf.jaas]):
  file:/.../etc/org.apache.karaf.jaas.cfg
org.apache.karaf.kar.internal.osgi.Activator - CM Configuration Updater (ManagedService Update: pid=[org.apache.karaf.kar]):
  file:/.../etc/org.apache.karaf.kar.cfg
org.apache.karaf.log.core.internal.osgi.Activator - CM Configuration Updater (ManagedService Update: pid=[org.apache.karaf.log]):
  file:/.../etc/org.apache.karaf.log.cfg
org.apache.karaf.management.internal.Activator - CM Configuration Updater (ManagedService Update: pid=[org.apache.karaf.management]):
  file:/.../etc/org.apache.karaf.management.cfg
org.apache.karaf.shell.ssh.Activator - CM Configuration Updater (ManagedService Update: pid=[org.apache.karaf.shell]):
  file:/.../etc/org.apache.karaf.shell.cfg

Issue Links

• duplicates: KARAF-6534 Conflict with instances of Karaf for JMX connection
• is duplicated by: KARAF-6224 Race condition in BaseActivator on first launch