Handling custom exception serialisation for plugins

Bukhtawar_Khan · December 21, 2020, 7:37am

The wire serialization of exceptions require exceptions to be registered. For instance if the transport node(transport inter-node communication) throws a custom exception, the caller node at transport needs to handle this and throw it appropriately to clients. However I couldn't find a way for plugins to be register the custom exception.

github.com

elastic/elasticsearch/blob/master/server/src/main/java/org/elasticsearch/ElasticsearchException.java#L734


    return throwable;
}
/**
 * This is the list of Exceptions Elasticsearch can throw over the wire or save into a corruption marker. Each value in the enum is a
 * single exception tying the Class to an id for use of the encode side and the id back to a constructor for use on the decode side. As
 * such its ok if the exceptions to change names so long as their constructor can still read the exception. Each exception is listed
 * in id order below. If you want to remove an exception leave a tombstone comment and mark the id as null in
 * ExceptionSerializationTests.testIds.ids.
 */
private enum ElasticsearchExceptionHandle {
    INDEX_SHARD_SNAPSHOT_FAILED_EXCEPTION(org.elasticsearch.index.snapshots.IndexShardSnapshotFailedException.class,
            org.elasticsearch.index.snapshots.IndexShardSnapshotFailedException::new, 0, UNKNOWN_VERSION_ADDED),
    DFS_PHASE_EXECUTION_EXCEPTION(org.elasticsearch.search.dfs.DfsPhaseExecutionException.class,
            org.elasticsearch.search.dfs.DfsPhaseExecutionException::new, 1, UNKNOWN_VERSION_ADDED),
    EXECUTION_CANCELLED_EXCEPTION(org.elasticsearch.common.util.CancellableThreads.ExecutionCancelledException.class,
            org.elasticsearch.common.util.CancellableThreads.ExecutionCancelledException::new, 2, UNKNOWN_VERSION_ADDED),
    MASTER_NOT_DISCOVERED_EXCEPTION(org.elasticsearch.discovery.MasterNotDiscoveredException.class,
            org.elasticsearch.discovery.MasterNotDiscoveredException::new, 3, UNKNOWN_VERSION_ADDED),
    ELASTICSEARCH_SECURITY_EXCEPTION(org.elasticsearch.ElasticsearchSecurityException.class,
            org.elasticsearch.ElasticsearchSecurityException::new, 4, UNKNOWN_VERSION_ADDED),

As a result the exceptions get wrapped in a NotSerializableExceptionWrapper.
Is there a way to handle this effectively or is the expectation/recommendation to unwrap the NotSerializableExceptionWrapper and rethrow the appropriate exception.

github.com

elastic/elasticsearch/blob/master/server/src/main/java/org/elasticsearch/common/io/stream/NotSerializableExceptionWrapper.java#L35


import java.io.IOException;
/**
 * This exception can be used to wrap a given, not serializable exception
 * to serialize via {@link StreamOutput#writeException(Throwable)}.
 * This class will preserve the stacktrace as well as the suppressed exceptions of
 * the throwable it was created with instead of it's own. The stacktrace has no indication
 * of where this exception was created.
 */
public final class NotSerializableExceptionWrapper extends ElasticsearchException {
    private final String name;
    private final RestStatus status;
    public NotSerializableExceptionWrapper(Throwable other) {
        super(ElasticsearchException.getExceptionName(other) + ": " + other.getMessage(), other.getCause());
        this.name = ElasticsearchException.getExceptionName(other);
        this.status = ExceptionsHelper.status(other);
        setStackTrace(other.getStackTrace());
        for (Throwable otherSuppressed : other.getSuppressed()) {

system · January 18, 2021, 7:37am

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