ableegoldman commented on a change in pull request #10683:
URL: https://github.com/apache/kafka/pull/10683#discussion_r669211161
##########
File path:
streams/src/main/java/org/apache/kafka/streams/processor/internals/TopologyMetadata.java
##########
@@ -16,10 +16,294 @@
*/
package org.apache.kafka.streams.processor.internals;
+import org.apache.kafka.clients.consumer.OffsetResetStrategy;
+import org.apache.kafka.common.TopicPartition;
+import org.apache.kafka.streams.StreamsConfig;
+import org.apache.kafka.streams.errors.TopologyException;
+import org.apache.kafka.streams.processor.StateStore;
+import org.apache.kafka.streams.processor.TaskId;
+import
org.apache.kafka.streams.processor.internals.InternalTopologyBuilder.TopicsInfo;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
import java.util.Objects;
+import java.util.Set;
+import java.util.SortedMap;
+import java.util.TreeMap;
+import java.util.function.Consumer;
+import java.util.function.Function;
+import java.util.regex.Pattern;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+// TODO KAFKA-12648:
+// 1) synchronize on these methods instead of individual
InternalTopologyBuilder methods, where applicable
public class TopologyMetadata {
- //TODO KAFKA-12648: the TopologyMetadata class is filled in by Pt. 2 (PR
#10683)
+ private final Logger log = LoggerFactory.getLogger(TopologyMetadata.class);
+
+ // the '_' character is not allowed for topology names, thus it's safe to
use to indicate that it's not a named topology
+ private static final String UNNAMED_TOPOLOGY = "__UNNAMED_TOPOLOGY__";
+ private static final Pattern EMPTY_ZERO_LENGTH_PATTERN =
Pattern.compile("");
+
+ private final StreamsConfig config;
+ private final SortedMap<String, InternalTopologyBuilder> builders; // Keep
sorted by topology name for readability
+
+ private ProcessorTopology globalTopology;
+ private Map<String, StateStore> globalStateStores = new HashMap<>();
+ final Set<String> allInputTopics = new HashSet<>();
+
+ public TopologyMetadata(final InternalTopologyBuilder builder, final
StreamsConfig config) {
+ this.config = config;
+ builders = new TreeMap<>();
+ if (builder.hasNamedTopology()) {
+ builders.put(builder.namedTopology(), builder);
+ } else {
+ builders.put(UNNAMED_TOPOLOGY, builder);
+ }
+ }
+
+ public TopologyMetadata(final SortedMap<String, InternalTopologyBuilder>
builders, final StreamsConfig config) {
+ this.config = config;
+ this.builders = builders;
+ if (builders.isEmpty()) {
+ log.debug("Building KafkaStreams app with no empty topology");
+ }
+ }
+
+ public int getNumStreamThreads(final StreamsConfig config) {
+ final int configuredNumStreamThreads =
config.getInt(StreamsConfig.NUM_STREAM_THREADS_CONFIG);
+
+ // If the application uses named topologies, it's possible to start up
with no topologies at all and only add them later
+ if (builders.isEmpty()) {
+ if (configuredNumStreamThreads != 0) {
+ log.info("Overriding number of StreamThreads to zero for empty
topology");
+ }
+ return 0;
+ }
+
+ // If there are topologies but they are all empty, this indicates a
bug in user code
+ if (hasNoNonGlobalTopology() && !hasGlobalTopology()) {
Review comment:
@guozhangwang WDYT? If the user has started up Streams with several
named topologies, but a subset of them are completely empty, should this be
considered user error and cause Streams to shutdown or should we just roll with
it as long as at least one topology is non-empty?
Take a look at the current state and lmk what you think
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
