001/* 002 * (C) Copyright 2017 Nuxeo SA (http://nuxeo.com/) and others. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 * 016 * Contributors: 017 * bdelbosc 018 */ 019package org.nuxeo.lib.stream.computation; 020 021import java.time.Duration; 022import java.util.Map; 023 024import org.nuxeo.lib.stream.log.Latency; 025 026/** 027 * Run a topology of computations according to some settings. 028 * 029 * @since 9.3 030 */ 031public interface StreamProcessor { 032 033 /** 034 * Initialize streams, but don't run the computations 035 */ 036 StreamProcessor init(Topology topology, Settings settings); 037 038 /** 039 * Run the initialized computations. 040 */ 041 void start(); 042 043 /** 044 * Try to stop computations gracefully after processing a record or a timer within the timeout duration. If this can 045 * not be done within the timeout, shutdown and returns false. 046 */ 047 boolean stop(Duration timeout); 048 049 /** 050 * Stop computations when input streams are empty. The timeout is applied for each computation, the total duration 051 * can be up to nb computations * timeout 052 * <p> 053 * Returns {@code true} if computations are stopped during the timeout delay. 054 */ 055 boolean drainAndStop(Duration timeout); 056 057 /** 058 * Shutdown immediately. 059 */ 060 void shutdown(); 061 062 /** 063 * Returns the low watermark for the computation. Any message with an offset below the low watermark has been 064 * processed by this computation and its ancestors. The returned watermark is local to this processing node, if the 065 * computation is distributed the global low watermark is the minimum of all nodes low watermark. 066 */ 067 long getLowWatermark(String computationName); 068 069 /** 070 * Returns the low watermark for all the computations of the topology. Any message with an offset below the low 071 * watermark has been processed. The returned watermark is local to this processing node. 072 */ 073 long getLowWatermark(); 074 075 /** 076 * Returns the latency for a computation. This works also for distributed computations. 077 * 078 * @since 10.1 079 */ 080 Latency getLatency(String computationName); 081 082 /** 083 * Returns true if all messages with a lower timestamp has been processed by the topology. 084 */ 085 boolean isDone(long timestamp); 086 087 /** 088 * Wait for the computations to have assigned partitions ready to process records. The processor must be started. 089 * This is useful for writing unit test. 090 * <p> 091 * Returns {@code true} if all computations have assigned partitions during the timeout delay. 092 */ 093 boolean waitForAssignments(Duration timeout) throws InterruptedException; 094 095 /** 096 * True if there is no active processing threads. 097 * 098 * @since 10.1 099 */ 100 boolean isTerminated(); 101 102 /** 103 * Returns a JSON representation of the processor, this includes the list of streams and computations with their 104 * settings along with the topology. 105 * 106 * @since 11.5 107 */ 108 String toJson(Map<String, String> meta); 109}