{"record":{"id":"4c3a5e968e862ec9","repo":"prestodb/presto","slug":"already-exists-4c3a5e","errorCode":"ALREADY_EXISTS","errorMessage":"A factory with the name '' is already registered.","messagePattern":"A factory with the name '' is already registered\\.","errorType":"error_code","errorClass":"PrestoException","httpStatus":null,"severity":"error","filePath":"presto-main-base/src/main/java/com/facebook/presto/ClientRequestFilterManager.java","lineNumber":51,"sourceCode":"\n@ThreadSafe\npublic class ClientRequestFilterManager\n{\n    private Map<String, ClientRequestFilterFactory> factories = new ConcurrentHashMap<>();\n\n    @GuardedBy(\"this\")\n    private volatile List<ClientRequestFilter> filters = ImmutableList.of();\n    private final AtomicBoolean loaded = new AtomicBoolean();\n\n    public void registerClientRequestFilterFactory(ClientRequestFilterFactory factory)\n    {\n        if (loaded.get()) {\n            throw new PrestoException(INVALID_ARGUMENTS, \"Cannot register factories after filters are loaded.\");\n        }\n\n        String name = factory.getName();\n        if (factories.putIfAbsent(name, factory) != null) {\n            throw new PrestoException(ALREADY_EXISTS, \"A factory with the name '\" + name + \"' is already registered.\");\n        }\n    }\n\n    public void loadClientRequestFilters()\n    {\n        if (!loaded.compareAndSet(false, true)) {\n            throw new PrestoException(CONFIGURATION_INVALID, \"loadClientRequestFilters can only be called once.\");\n        }\n\n        filters = factories.values().stream()\n                .map(factory -> factory.create())\n                .collect(toImmutableList());\n        factories = null;\n    }\n\n    public List<ClientRequestFilter> getClientRequestFilters()\n    {\n        return filters;","sourceCodeStart":33,"sourceCodeEnd":69,"githubUrl":"https://github.com/prestodb/presto/blob/55bb57d202de3b926896fa966c2c4a44c779634e/presto-main-base/src/main/java/com/facebook/presto/ClientRequestFilterManager.java#L33-L69","documentation":"registerClientRequestFilterFactory guard: a ClientRequestFilterFactory with the same name was already registered (putIfAbsent returned a prior entry), so duplicate registration is refused with ALREADY_EXISTS.","triggerScenarios":"Thrown at presto-main-base/src/main/java/com/facebook/presto/ClientRequestFilterManager.java:51 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Give the factory a unique name","Remove the duplicate plugin or duplicate registration in the classpath"],"exampleFix":null,"handlingStrategy":"validation","validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"55bb57d202de3b926896fa966c2c4a44c779634e","analyzedAt":"2026-09-04T12:50:26.162Z","contentChangedAt":"2026-09-04T12:50:26.162Z","schemaVersion":2},"datasetVersion":"2026-09-11T21:17:09.523Z"}