@Override
public void shutdown(IRecordProcessorCheckpointer checkpointer, ShutdownReason reason) {
// In cases where KCL loses lease for the shard after creating record processor instance but
// before
// record processor initialize() is called, then shutdown() may be called directly before
// initialize().
if (!initialized) {
LOG.info(
"Record processor was not initialized and will not have a child process, "
+ "so not invoking child process shutdown.");
this.state = ProcessState.SHUTDOWN;
return;
}
try {
if (ProcessState.ACTIVE.equals(this.state)) {
if (!protocol.shutdown(checkpointer, reason)) {
throw new RuntimeException("Child process failed to shutdown");
}
childProcessShutdownSequence();
} else {
LOG.warn("Shutdown was called but this processor is already shutdown. Not doing anything.");
}
} catch (Throwable t) {
if (ProcessState.ACTIVE.equals(this.state)) {
stopProcessing("Encountered an error while trying to shutdown child process", t);
} else {
stopProcessing(
"Encountered an error during shutdown,"
+ " but it appears the processor has already been shutdown",
t);
}
}
}
@Override
public void initialize(String shardIdToProcess) {
try {
this.shardId = shardIdToProcess;
try {
this.process = startProcess();
} catch (IOException e) {
/*
* The process builder has thrown an exception while starting the child process so we would like to shut
* down
*/
throw new IOException("Failed to start client executable", e);
}
// Initialize all of our utility objects that will handle interacting with the process over
// STDIN/STDOUT/STDERR
messageWriter.initialize(process.getOutputStream(), shardId, objectMapper, executorService);
messageReader.initialize(process.getInputStream(), shardId, objectMapper, executorService);
readSTDERRTask.initialize(process.getErrorStream(), shardId, "Reading STDERR for " + shardId);
// Submit the error reader for execution
stderrReadTask = executorService.submit(readSTDERRTask);
protocol = new MultiLangProtocol(messageReader, messageWriter, shardId);
if (!protocol.initialize()) {
throw new RuntimeException("Failed to initialize child process");
}
initialized = true;
} catch (Throwable t) {
// Any exception in initialize results in MultiLangDaemon shutdown.
stopProcessing("Encountered an error while trying to initialize record processor", t);
}
}
@Override
public void processRecords(List<Record> records, IRecordProcessorCheckpointer checkpointer) {
try {
if (!protocol.processRecords(records, checkpointer)) {
throw new RuntimeException("Child process failed to process records");
}
} catch (Throwable t) {
stopProcessing("Encountered an error while trying to process records", t);
}
}