/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. 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 the License. You may obtain a copy of the License at
*
* 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,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.zookeeper.server.admin;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.zookeeper.Environment;
import org.apache.zookeeper.Environment.Entry;
import org.apache.zookeeper.Version;
import org.apache.zookeeper.server.DataTree;
import org.apache.zookeeper.server.ServerStats;
import org.apache.zookeeper.server.ZKDatabase;
import org.apache.zookeeper.server.ZooKeeperServer;
import org.apache.zookeeper.server.ZooTrace;
import org.apache.zookeeper.server.quorum.Leader;
import org.apache.zookeeper.server.quorum.LeaderZooKeeperServer;
import org.apache.zookeeper.server.quorum.ReadOnlyZooKeeperServer;
import org.apache.zookeeper.server.util.OSMXBean;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Class containing static methods for registering and running Commands, as well
* as default Command definitions.
*
* @see Command
* @see JettyAdminServer
*/
public class Commands {
static final Logger LOG = LoggerFactory.getLogger(Commands.class);
/** Maps command names to Command instances */
private static Map<String, Command> commands = new HashMap<String, Command>();
private static Set<String> primaryNames = new HashSet<String>();
/**
* Registers the given command. Registered commands can be run by passing
* any of their names to runCommand.
*/
public static void registerCommand(Command command) {
for (String name : command.getNames()) {
Command prev = commands.put(name, command);
if (prev != null) {
LOG.warn("Re-registering command %s (primary name = %s)", name, command.getPrimaryName());
}
}
primaryNames.add(command.getPrimaryName());
}
/**
* Run the registered command with name cmdName. Commands should not produce
* any exceptions; any (anticipated) errors should be reported in the
* "error" entry of the returned map. Likewise, if no command with the given
* name is registered, this will be noted in the "error" entry.
*
* @param cmdName
* @param zkServer
* @param kwargs String-valued keyword arguments to the command
* (may be null if command requires no additional arguments)
* @return Map representing response to command containing at minimum:
* - "command" key containing the command's primary name
* - "error" key containing a String error message or null if no error
*/
public static CommandResponse runCommand(String cmdName, ZooKeeperServer zkServer, Map<String, String> kwargs) {
if (!commands.containsKey(cmdName)) {
return new CommandResponse(cmdName, "Unknown command: " + cmdName);
}
if (zkServer == null) {
return new CommandResponse(cmdName, "This ZooKeeper instance is not currently serving requests");
}
return commands.get(cmdName).run(zkServer, kwargs);
}
/**
* Returns the primary names of all registered commands.
*/
public static Set<String> getPrimaryNames() {
return primaryNames;
}
/**
* Returns the commands registered under cmdName with registerCommand, or
* null if no command is registered with that name.
*/
public static Command getCommand(String cmdName) {
return commands.get(cmdName);
}
static {
registerCommand(new CnxnStatResetCommand());
registerCommand(new ConfCommand());
registerCommand(new ConsCommand());
registerCommand(new DumpCommand());
registerCommand(new EnvCommand());
registerCommand(new GetTraceMaskCommand());
registerCommand(new IsroCommand());
registerCommand(new MonitorCommand());
registerCommand(new RuokCommand());
registerCommand(new SetTraceMaskCommand());
registerCommand(new SrvrCommand());
registerCommand(new StatCommand());
registerCommand(new StatResetCommand());
registerCommand(new WatchCommand());
registerCommand(new WatchesByPathCommand());
registerCommand(new WatchSummaryCommand());
}
/**
* Reset all connection statistics.
*/
public static class CnxnStatResetCommand extends CommandBase {
public CnxnStatResetCommand() {
super(Arrays.asList("connection_stat_reset", "crst"));
}
@Override
public CommandResponse run(ZooKeeperServer zkServer, Map<String, String> kwargs) {
CommandResponse response = initializeResponse();
zkServer.getServerCnxnFactory().resetAllConnectionStats();
return response;
}
}
/**
* Server configuration parameters.
* @see ZooKeeperServer#getConf()
*/
public static class ConfCommand extends CommandBase {
public ConfCommand() {
super(Arrays.asList("configuration", "conf", "config"));
}
@Override
public CommandResponse run(ZooKeeperServer zkServer, Map<String, String> kwargs) {
CommandResponse response = initializeResponse();
response.putAll(zkServer.getConf().toMap());
return response;
}
}
/**
* Information on client connections to server. Returned Map contains:
* - "connections": list of connection info objects
* @see org.apache.zookeeper.server.ServerCnxn#getConnectionInfo(boolean)
*/
public static class ConsCommand extends CommandBase {
public ConsCommand() {
super(Arrays.asList("connections", "cons"));
}
@Override
public CommandResponse run(ZooKeeperServer zkServer, Map<String, String> kwargs) {
CommandResponse response = initializeResponse();
response.put("connections", zkServer.getServerCnxnFactory().getAllConnectionInfo(false));
return response;
}
}
/**
* Information on session expirations and ephemerals. Returned map contains:
* - "expiry_time_to_session_ids": Map<Long, Set<Long>>
* time -> sessions IDs of sessions that expire at time
* - "sesssion_id_to_ephemeral_paths": Map<Long, Set<String>>
* session ID -> ephemeral paths created by that session
* @see ZooKeeperServer#getSessionExpiryMap()
* @see ZooKeeperServer#getEphemerals()
*/
public static class DumpCommand extends CommandBase {
public DumpCommand() {
super(Arrays.asList("dump"));
}
@Override
public CommandResponse run(ZooKeeperServer zkServer, Map<String, String> kwargs) {
CommandResponse response = initializeResponse();
response.put("expiry_time_to_session_ids", zkServer.getSessionExpiryMap());
response.put("session_id_to_ephemeral_paths", zkServer.getEphemerals());
return response;
}
}
/**
* All defined environment variables.
*/
public static class EnvCommand extends CommandBase {
public EnvCommand() {
super(Arrays.asList("environment", "env", "envi"));
}
@Override
public CommandResponse run(ZooKeeperServer zkServer, Map<String, String> kwargs) {
CommandResponse response = initializeResponse();
for (Entry e : Environment.list()) {
response.put(e.getKey(), e.getValue());
}
return response;
}
}
/**
* The current trace mask. Returned map contains:
* - "tracemask": Long
*/
public static class GetTraceMaskCommand extends CommandBase {
public GetTraceMaskCommand() {
super(Arrays.asList("get_trace_mask", "gtmk"));
}
@Override
public CommandResponse run(ZooKeeperServer zkServer, Map<String, String> kwargs) {
CommandResponse response = initializeResponse();
response.put("tracemask", ZooTrace.getTextTraceLevel());
return response;
}
}
/**
* Is this server in read-only mode. Returned map contains:
* - "is_read_only": Boolean
*/
public static class IsroCommand extends CommandBase {
public IsroCommand() {
super(Arrays.asList("is_read_only", "isro"));
}
@Override
public CommandResponse run(ZooKeeperServer zkServer, Map<String, String> kwargs) {
CommandResponse response = initializeResponse();
response.put("read_only", zkServer instanceof ReadOnlyZooKeeperServer);
return response;
}
}
/**
* Some useful info for monitoring. Returned map contains:
* - "version": String
* server version
* - "avg_latency": Long
* - "max_latency": Long
* - "min_latency": Long
* - "packets_received": Long
* - "packets_sents": Long
* - "num_alive_connections": Integer
* - "outstanding_requests": Long
* number of unprocessed requests
* - "server_state": "leader", "follower", or "standalone"
* - "znode_count": Integer
* - "watch_count": Integer
* - "ephemerals_count": Integer
* - "approximate_data_size": Long
* - "open_file_descriptor_count": Long (unix only)
* - "max_file_descritpor_count": Long (unix only)
* - "followers": Integer (leader only)
* - "synced_followers": Integer (leader only)
* - "pending_syncs": Integer (leader only)
*/
public static class MonitorCommand extends CommandBase {
public MonitorCommand() {
super(Arrays.asList("monitor", "mntr"));
}
@Override
public CommandResponse run(ZooKeeperServer zkServer, Map<String, String> kwargs) {
ZKDatabase zkdb = zkServer.getZKDatabase();
ServerStats stats = zkServer.serverStats();
CommandResponse response = initializeResponse();
response.put("version", Version.getFullVersion());
response.put("avg_latency", stats.getAvgLatency());
response.put("max_latency", stats.getMaxLatency());
response.put("min_latency", stats.getMinLatency());
response.put("packets_received", stats.getPacketsReceived());
response.put("packets_sent", stats.getPacketsSent());
response.put("num_alive_connections", stats.getNumAliveClientConnections());
response.put("outstanding_requests", stats.getOutstandingRequests());
response.put("server_state", stats.getServerState());
response.put("znode_count", zkdb.getNodeCount());
response.put("watch_count", zkdb.getDataTree().getWatchCount());
response.put("ephemerals_count", zkdb.getDataTree().getEphemeralsCount());
response.put("approximate_data_size", zkdb.getDataTree().approximateDataSize());
OSMXBean osMbean = new OSMXBean();
response.put("open_file_descriptor_count", osMbean.getOpenFileDescriptorCount());
response.put("max_file_descriptor_count", osMbean.getMaxFileDescriptorCount());
if (zkServer instanceof LeaderZooKeeperServer) {
Leader leader = ((LeaderZooKeeperServer) zkServer).getLeader();
response.put("followers", leader.getLearners().size());
response.put("synced_followers", leader.getForwardingFollowers().size());
response.put("pending_syncs", leader.getNumPendingSyncs());
}
return response;
}}
/**
* No-op command, check if the server is running
*/
public static class RuokCommand extends CommandBase {
public RuokCommand() {
super(Arrays.asList("ruok"));
}
@Override
public CommandResponse run(ZooKeeperServer zkServer, Map<String, String> kwargs) {
return initializeResponse();
}
}
/**
* Sets the trace mask. Required arguments:
* - "traceMask": Long
* Returned Map contains:
* - "tracemask": Long
*/
public static class SetTraceMaskCommand extends CommandBase {
public SetTraceMaskCommand() {
super(Arrays.asList("set_trace_mask", "stmk"));
}
@Override
public CommandResponse run(ZooKeeperServer zkServer, Map<String, String> kwargs) {
CommandResponse response = initializeResponse();
long traceMask;
if (!kwargs.containsKey("traceMask")) {
response.put("error", "setTraceMask requires long traceMask argument");
return response;
}
try {
traceMask = Long.parseLong(kwargs.get("traceMask"));
} catch (NumberFormatException e) {
response.put("error", "setTraceMask requires long traceMask argument, got "
+ kwargs.get("traceMask"));
return response;
}
ZooTrace.setTextTraceLevel(traceMask);
response.put("tracemask", traceMask);
return response;
}
}
/**
* Server information. Returned map contains:
* - "version": String
* version of server
* - "read_only": Boolean
* is server in read-only mode
* - "server_stats": ServerStats object
* - "node_count": Integer
*/
public static class SrvrCommand extends CommandBase {
public SrvrCommand() {
super(Arrays.asList("server_stats", "srvr"));
}
// Allow subclasses (e.g. StatCommand) to specify their own names
protected SrvrCommand(List<String> names) {
super(names);
}
@Override
public CommandResponse run(ZooKeeperServer zkServer, Map<String, String> kwargs) {
CommandResponse response = initializeResponse();
LOG.info("running stat");
response.put("version", Version.getFullVersion());
response.put("read_only", zkServer instanceof ReadOnlyZooKeeperServer);
response.put("server_stats", zkServer.serverStats());
response.put("node_count", zkServer.getZKDatabase().getNodeCount());
return response;
}
}
/**
* Same as SrvrCommand but has extra "connections" entry.
*/
public static class StatCommand extends SrvrCommand {
public StatCommand() {
super(Arrays.asList("stats", "stat"));
}
@Override
public CommandResponse run(ZooKeeperServer zkServer, Map<String, String> kwargs) {
CommandResponse response = super.run(zkServer, kwargs);
response.put("connections", zkServer.getServerCnxnFactory().getAllConnectionInfo(true));
return response;
}
}
/**
* Resets server statistics.
*/
public static class StatResetCommand extends CommandBase {
public StatResetCommand() {
super(Arrays.asList("stat_reset", "srst"));
}
@Override
public CommandResponse run(ZooKeeperServer zkServer, Map<String, String> kwargs) {
CommandResponse response = initializeResponse();
zkServer.serverStats().reset();
return response;
}
}
/**
* Watch information aggregated by session. Returned Map contains:
* - "session_id_to_watched_paths": Map<Long, Set<String>> session ID -> watched paths
* @see DataTree#getWatches()
*/
public static class WatchCommand extends CommandBase {
public WatchCommand() {
super(Arrays.asList("watches", "wchc"));
}
@Override
public CommandResponse run(ZooKeeperServer zkServer, Map<String, String> kwargs) {
DataTree dt = zkServer.getZKDatabase().getDataTree();
CommandResponse response = initializeResponse();
response.put("session_id_to_watched_paths", dt.getWatches().toMap());
return response;
}
}
/**
* Watch information aggregated by path. Returned Map contains:
* - "path_to_session_ids": Map<String, Set<Long>> path -> session IDs of sessions watching path
* @see DataTree#getWatchesByPath()
*/
public static class WatchesByPathCommand extends CommandBase {
public WatchesByPathCommand() {
super(Arrays.asList("watches_by_path", "wchp"));
}
@Override
public CommandResponse run(ZooKeeperServer zkServer, Map<String, String> kwargs) {
DataTree dt = zkServer.getZKDatabase().getDataTree();
CommandResponse response = initializeResponse();
response.put("path_to_session_ids", dt.getWatchesByPath().toMap());
return response;
}
}
/**
* Summarized watch information.
* @see DataTree#getWatchesSummary()
*/
public static class WatchSummaryCommand extends CommandBase {
public WatchSummaryCommand() {
super(Arrays.asList("watch_summary", "wchs"));
}
@Override
public CommandResponse run(ZooKeeperServer zkServer, Map<String, String> kwargs) {
DataTree dt = zkServer.getZKDatabase().getDataTree();
CommandResponse response = initializeResponse();
response.putAll(dt.getWatchesSummary().toMap());
return response;
}
}
private Commands() {}
}