org.apache.kafka.connect.runtime.AbstractHerder Maven / Gradle / Ivy
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* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
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* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
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* See the License for the specific language governing permissions and
* limitations under the License.
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package org.apache.kafka.connect.runtime;
import org.apache.kafka.common.config.Config;
import org.apache.kafka.common.config.ConfigDef;
import org.apache.kafka.common.config.ConfigDef.ConfigKey;
import org.apache.kafka.common.config.ConfigDef.Type;
import org.apache.kafka.common.config.ConfigValue;
import org.apache.kafka.connect.connector.Connector;
import org.apache.kafka.connect.errors.NotFoundException;
import org.apache.kafka.connect.runtime.isolation.Plugins;
import org.apache.kafka.connect.runtime.rest.entities.ConfigInfo;
import org.apache.kafka.connect.runtime.rest.entities.ConfigInfos;
import org.apache.kafka.connect.runtime.rest.entities.ConfigKeyInfo;
import org.apache.kafka.connect.runtime.rest.entities.ConfigValueInfo;
import org.apache.kafka.connect.runtime.rest.entities.ConnectorInfo;
import org.apache.kafka.connect.runtime.rest.entities.ConnectorStateInfo;
import org.apache.kafka.connect.runtime.rest.entities.ConnectorType;
import org.apache.kafka.connect.runtime.rest.errors.BadRequestException;
import org.apache.kafka.connect.source.SourceConnector;
import org.apache.kafka.connect.storage.ConfigBackingStore;
import org.apache.kafka.connect.storage.StatusBackingStore;
import org.apache.kafka.connect.util.Callback;
import org.apache.kafka.connect.util.ConnectorTaskId;
import java.io.ByteArrayOutputStream;
import java.io.PrintStream;
import java.io.UnsupportedEncodingException;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
/**
* Abstract Herder implementation which handles connector/task lifecycle tracking. Extensions
* must invoke the lifecycle hooks appropriately.
*
* This class takes the following approach for sending status updates to the backing store:
*
* 1) When the connector or task is starting, we overwrite the previous state blindly. This ensures that
* every rebalance will reset the state of tasks to the proper state. The intuition is that there should
* be less chance of write conflicts when the worker has just received its assignment and is starting tasks.
* In particular, this prevents us from depending on the generation absolutely. If the group disappears
* and the generation is reset, then we'll overwrite the status information with the older (and larger)
* generation with the updated one. The danger of this approach is that slow starting tasks may cause the
* status to be overwritten after a rebalance has completed.
*
* 2) If the connector or task fails or is shutdown, we use {@link StatusBackingStore#putSafe(ConnectorStatus)},
* which provides a little more protection if the worker is no longer in the group (in which case the
* task may have already been started on another worker). Obviously this is still racy. If the task has just
* started on another worker, we may not have the updated status cached yet. In this case, we'll overwrite
* the value which will cause the state to be inconsistent (most likely until the next rebalance). Until
* we have proper producer groups with fenced groups, there is not much else we can do.
*/
public abstract class AbstractHerder implements Herder, TaskStatus.Listener, ConnectorStatus.Listener {
private final String workerId;
protected final Worker worker;
private final String kafkaClusterId;
protected final StatusBackingStore statusBackingStore;
protected final ConfigBackingStore configBackingStore;
private Map tempConnectors = new ConcurrentHashMap<>();
public AbstractHerder(Worker worker,
String workerId,
String kafkaClusterId,
StatusBackingStore statusBackingStore,
ConfigBackingStore configBackingStore) {
this.worker = worker;
this.worker.herder = this;
this.workerId = workerId;
this.kafkaClusterId = kafkaClusterId;
this.statusBackingStore = statusBackingStore;
this.configBackingStore = configBackingStore;
}
@Override
public String kafkaClusterId() {
return kafkaClusterId;
}
protected abstract int generation();
protected void startServices() {
this.worker.start();
this.statusBackingStore.start();
this.configBackingStore.start();
}
protected void stopServices() {
this.statusBackingStore.stop();
this.configBackingStore.stop();
this.worker.stop();
}
@Override
public void onStartup(String connector) {
statusBackingStore.put(new ConnectorStatus(connector, ConnectorStatus.State.RUNNING,
workerId, generation()));
}
@Override
public void onPause(String connector) {
statusBackingStore.put(new ConnectorStatus(connector, ConnectorStatus.State.PAUSED,
workerId, generation()));
}
@Override
public void onResume(String connector) {
statusBackingStore.put(new ConnectorStatus(connector, TaskStatus.State.RUNNING,
workerId, generation()));
}
@Override
public void onShutdown(String connector) {
statusBackingStore.putSafe(new ConnectorStatus(connector, ConnectorStatus.State.UNASSIGNED,
workerId, generation()));
}
@Override
public void onFailure(String connector, Throwable cause) {
statusBackingStore.putSafe(new ConnectorStatus(connector, ConnectorStatus.State.FAILED,
trace(cause), workerId, generation()));
}
@Override
public void onStartup(ConnectorTaskId id) {
statusBackingStore.put(new TaskStatus(id, TaskStatus.State.RUNNING, workerId, generation()));
}
@Override
public void onFailure(ConnectorTaskId id, Throwable cause) {
statusBackingStore.putSafe(new TaskStatus(id, TaskStatus.State.FAILED, workerId, generation(), trace(cause)));
}
@Override
public void onShutdown(ConnectorTaskId id) {
statusBackingStore.putSafe(new TaskStatus(id, TaskStatus.State.UNASSIGNED, workerId, generation()));
}
@Override
public void onResume(ConnectorTaskId id) {
statusBackingStore.put(new TaskStatus(id, TaskStatus.State.RUNNING, workerId, generation()));
}
@Override
public void onPause(ConnectorTaskId id) {
statusBackingStore.put(new TaskStatus(id, TaskStatus.State.PAUSED, workerId, generation()));
}
@Override
public void onDeletion(String connector) {
for (TaskStatus status : statusBackingStore.getAll(connector))
statusBackingStore.put(new TaskStatus(status.id(), TaskStatus.State.DESTROYED, workerId, generation()));
statusBackingStore.put(new ConnectorStatus(connector, ConnectorStatus.State.DESTROYED, workerId, generation()));
}
@Override
public void pauseConnector(String connector) {
if (!configBackingStore.contains(connector))
throw new NotFoundException("Unknown connector " + connector);
configBackingStore.putTargetState(connector, TargetState.PAUSED);
}
@Override
public void resumeConnector(String connector) {
if (!configBackingStore.contains(connector))
throw new NotFoundException("Unknown connector " + connector);
configBackingStore.putTargetState(connector, TargetState.STARTED);
}
@Override
public Plugins plugins() {
return worker.getPlugins();
}
/*
* Retrieves config map by connector name
*/
protected abstract Map config(String connName);
@Override
public ConnectorStateInfo connectorStatus(String connName) {
ConnectorStatus connector = statusBackingStore.get(connName);
if (connector == null)
throw new NotFoundException("No status found for connector " + connName);
Collection tasks = statusBackingStore.getAll(connName);
ConnectorStateInfo.ConnectorState connectorState = new ConnectorStateInfo.ConnectorState(
connector.state().toString(), connector.workerId(), connector.trace());
List taskStates = new ArrayList<>();
for (TaskStatus status : tasks) {
taskStates.add(new ConnectorStateInfo.TaskState(status.id().task(),
status.state().toString(), status.workerId(), status.trace()));
}
Collections.sort(taskStates);
Map conf = config(connName);
return new ConnectorStateInfo(connName, connectorState, taskStates,
conf == null ? ConnectorType.UNKNOWN : connectorTypeForClass(conf.get(ConnectorConfig.CONNECTOR_CLASS_CONFIG)));
}
@Override
public ConnectorStateInfo.TaskState taskStatus(ConnectorTaskId id) {
TaskStatus status = statusBackingStore.get(id);
if (status == null)
throw new NotFoundException("No status found for task " + id);
return new ConnectorStateInfo.TaskState(id.task(), status.state().toString(),
status.workerId(), status.trace());
}
protected Map validateBasicConnectorConfig(Connector connector,
ConfigDef configDef,
Map config) {
return configDef.validateAll(config);
}
@Override
public ConfigInfos validateConnectorConfig(Map connectorProps) {
String connType = connectorProps.get(ConnectorConfig.CONNECTOR_CLASS_CONFIG);
if (connType == null)
throw new BadRequestException("Connector config " + connectorProps + " contains no connector type");
Connector connector = getConnector(connType);
ClassLoader savedLoader = plugins().compareAndSwapLoaders(connector);
try {
ConfigDef baseConfigDef;
if (connector instanceof SourceConnector) {
baseConfigDef = SourceConnectorConfig.configDef();
} else {
baseConfigDef = SinkConnectorConfig.configDef();
SinkConnectorConfig.validate(connectorProps);
}
ConfigDef enrichedConfigDef = ConnectorConfig.enrich(plugins(), baseConfigDef, connectorProps, false);
Map validatedConnectorConfig = validateBasicConnectorConfig(
connector,
enrichedConfigDef,
connectorProps
);
List configValues = new ArrayList<>(validatedConnectorConfig.values());
Map configKeys = new LinkedHashMap<>(enrichedConfigDef.configKeys());
Set allGroups = new LinkedHashSet<>(enrichedConfigDef.groups());
// do custom connector-specific validation
Config config = connector.validate(connectorProps);
if (null == config) {
throw new BadRequestException(
String.format(
"%s.validate() must return a Config that is not null.",
connector.getClass().getName()
)
);
}
ConfigDef configDef = connector.config();
if (null == configDef) {
throw new BadRequestException(
String.format(
"%s.config() must return a ConfigDef that is not null.",
connector.getClass().getName()
)
);
}
configKeys.putAll(configDef.configKeys());
allGroups.addAll(configDef.groups());
configValues.addAll(config.configValues());
return generateResult(connType, configKeys, configValues, new ArrayList<>(allGroups));
} finally {
Plugins.compareAndSwapLoaders(savedLoader);
}
}
// public for testing
public static ConfigInfos generateResult(String connType, Map configKeys, List configValues, List groups) {
int errorCount = 0;
List configInfoList = new LinkedList<>();
Map configValueMap = new HashMap<>();
for (ConfigValue configValue: configValues) {
String configName = configValue.name();
configValueMap.put(configName, configValue);
if (!configKeys.containsKey(configName)) {
configValue.addErrorMessage("Configuration is not defined: " + configName);
configInfoList.add(new ConfigInfo(null, convertConfigValue(configValue, null)));
}
}
for (Map.Entry entry : configKeys.entrySet()) {
String configName = entry.getKey();
ConfigKeyInfo configKeyInfo = convertConfigKey(entry.getValue());
Type type = entry.getValue().type;
ConfigValueInfo configValueInfo = null;
if (configValueMap.containsKey(configName)) {
ConfigValue configValue = configValueMap.get(configName);
configValueInfo = convertConfigValue(configValue, type);
errorCount += configValue.errorMessages().size();
}
configInfoList.add(new ConfigInfo(configKeyInfo, configValueInfo));
}
return new ConfigInfos(connType, errorCount, groups, configInfoList);
}
private static ConfigKeyInfo convertConfigKey(ConfigKey configKey) {
String name = configKey.name;
Type type = configKey.type;
String typeName = configKey.type.name();
boolean required = false;
String defaultValue;
if (ConfigDef.NO_DEFAULT_VALUE.equals(configKey.defaultValue)) {
defaultValue = null;
required = true;
} else {
defaultValue = ConfigDef.convertToString(configKey.defaultValue, type);
}
String importance = configKey.importance.name();
String documentation = configKey.documentation;
String group = configKey.group;
int orderInGroup = configKey.orderInGroup;
String width = configKey.width.name();
String displayName = configKey.displayName;
List dependents = configKey.dependents;
return new ConfigKeyInfo(name, typeName, required, defaultValue, importance, documentation, group, orderInGroup, width, displayName, dependents);
}
private static ConfigValueInfo convertConfigValue(ConfigValue configValue, Type type) {
String value = ConfigDef.convertToString(configValue.value(), type);
List recommendedValues = new LinkedList<>();
if (type == Type.LIST) {
for (Object object: configValue.recommendedValues()) {
recommendedValues.add(ConfigDef.convertToString(object, Type.STRING));
}
} else {
for (Object object : configValue.recommendedValues()) {
recommendedValues.add(ConfigDef.convertToString(object, type));
}
}
return new ConfigValueInfo(configValue.name(), value, recommendedValues, configValue.errorMessages(), configValue.visible());
}
protected Connector getConnector(String connType) {
if (tempConnectors.containsKey(connType)) {
return tempConnectors.get(connType);
} else {
Connector connector = plugins().newConnector(connType);
tempConnectors.put(connType, connector);
return connector;
}
}
/*
* Retrieves ConnectorType for the corresponding connector class
* @param connClass class of the connector
*/
public ConnectorType connectorTypeForClass(String connClass) {
return ConnectorType.from(getConnector(connClass).getClass());
}
/**
* Checks a given {@link ConfigInfos} for validation error messages and adds an exception
* to the given {@link Callback} if any were found.
*
* @param configInfos configInfos to read Errors from
* @param callback callback to add config error exception to
* @return true if errors were found in the config
*/
protected final boolean maybeAddConfigErrors(
ConfigInfos configInfos,
Callback> callback
) {
int errors = configInfos.errorCount();
boolean hasErrors = errors > 0;
if (hasErrors) {
StringBuilder messages = new StringBuilder();
messages.append("Connector configuration is invalid and contains the following ")
.append(errors).append(" error(s):");
for (ConfigInfo configInfo : configInfos.values()) {
for (String msg : configInfo.configValue().errors()) {
messages.append('\n').append(msg);
}
}
callback.onCompletion(
new BadRequestException(
messages.append(
"\nYou can also find the above list of errors at the endpoint `/{connectorType}/config/validate`"
).toString()
), null
);
}
return hasErrors;
}
private String trace(Throwable t) {
ByteArrayOutputStream output = new ByteArrayOutputStream();
try {
t.printStackTrace(new PrintStream(output, false, StandardCharsets.UTF_8.name()));
return output.toString("UTF-8");
} catch (UnsupportedEncodingException e) {
return null;
}
}
}
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