pinpoint-apm/pinpoint · warning

is not a directory

Error message

 is not a directory

What it means

AgentDirBaseClassPathResolver.resolvePlugins() logs this warning when the configured plugin directory path fails the checkDirectory() guard, i.e. the path either does not exist or exists but is not a directory. The resolver then returns an empty plugin list, so the agent boots without any plugins loaded. It is a diagnostic warning, not a thrown exception.

Solutions

1. Verify the plugin directory path actually exists: ls <agentDir>/plugin
2. If the path points at a JAR file, point it at the parent directory instead
3. Set -Dpinpoint.agent.pluginDir to a valid absolute directory path
4. Re-install/extract the Pinpoint agent distribution so the plugin folder exists
5. Check logs for the companion 'not found' vs 'is not a directory' warning to distinguish the two cases

Example fix

// before (launch script)
JAVA_OPTS="$JAVA_OPTS -Dpinpoint.agent.pluginDir=$AGENT_HOME/plugin/pinpoint-bootstrap-core.jar"
// after
JAVA_OPTS="$JAVA_OPTS -Dpinpoint.agent.pluginDir=$AGENT_HOME/plugin"

java.nio.Path p = Paths.get(pluginDir); if (!java.nio.Files.isDirectory(p)) { throw new IllegalArgumentException(pluginDir + " is not a directory"); }

When it happens

Trigger: Starting the Pinpoint agent when -Dpinpoint.agent.pluginDir (or the default ${AGENT_HOME}/plugin) points to a nonexistent path or to a regular file instead of a directory.

Common situations: AGENT_HOME misconfigured in the launch script; plugin dir renamed or deleted during upgrade; user pointed pluginDir at the plugin JAR file itself instead of the containing directory; packaged distribution missing the plugin folder.

Related errors

• too many
• Agent already started.
• - agentId
• - agentName
• AgentOption

AI-assisted analysis of pinpoint-apm/pinpoint@744c3d3075 (2026-09-07). Data as JSON: /api/errors/e921742eabead76b. Report an issue: GitHub.

Appendix: source

Thrown at agent-module/bootstraps/bootstrap/src/main/java/com/navercorp/pinpoint/bootstrap/agentdir/AgentDirBaseClassPathResolver.java:154

        if (checkDirectory(agentLibPath)) {
            return Collections.emptyList();
        }

        final List<Path> libFileList = FileUtils.listFiles(agentLibPath, EXTENSIONS);
        if (libFileList.isEmpty()) {
            throw new RuntimeException(agentLibPath + " lib dir is empty");
        }
        // add directory
        libFileList.add(agentLibPath);

        return libFileList;
    }

    private List<Path> resolvePlugins(Path agentPluginPath) {

        if (checkDirectory(agentPluginPath)) {
            logger.warn(agentPluginPath + " is not a directory");
            return Collections.emptyList();
        }

        final List<Path> jars = FileUtils.listFiles(agentPluginPath, "*.jar");
        if (jars.isEmpty()) {
            return Collections.emptyList();
        }

        List<Path> pluginFileList = filterReadPermission(jars);
        for (Path pluginJar : pluginFileList) {
            logger.info("plugin path:" + FileUtils.subpathAfterLast(pluginJar, 2));
        }
        return pluginFileList;
    }

    private boolean checkDirectory(Path file) {
        if (!Files.exists(file)) {
            logger.warn(file + " not found");

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