/**
* 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;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.List;
import org.apache.jute.Record;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.MultiResponse;
import org.apache.zookeeper.ZooDefs;
import org.apache.zookeeper.KeeperException.Code;
import org.apache.zookeeper.KeeperException.SessionMovedException;
import org.apache.zookeeper.ZooDefs.OpCode;
import org.apache.zookeeper.data.ACL;
import org.apache.zookeeper.data.Stat;
import org.apache.zookeeper.proto.CreateResponse;
import org.apache.zookeeper.proto.ExistsRequest;
import org.apache.zookeeper.proto.ExistsResponse;
import org.apache.zookeeper.proto.GetACLRequest;
import org.apache.zookeeper.proto.GetACLResponse;
import org.apache.zookeeper.proto.GetChildren2Request;
import org.apache.zookeeper.proto.GetChildren2Response;
import org.apache.zookeeper.proto.GetChildrenRequest;
import org.apache.zookeeper.proto.GetChildrenResponse;
import org.apache.zookeeper.proto.GetDataRequest;
import org.apache.zookeeper.proto.GetDataResponse;
import org.apache.zookeeper.proto.ReplyHeader;
import org.apache.zookeeper.proto.SetACLResponse;
import org.apache.zookeeper.proto.SetDataResponse;
import org.apache.zookeeper.proto.SetWatches;
import org.apache.zookeeper.proto.SyncRequest;
import org.apache.zookeeper.proto.SyncResponse;
import org.apache.zookeeper.server.DataTree.ProcessTxnResult;
import org.apache.zookeeper.server.ZooKeeperServer.ChangeRecord;
import org.apache.zookeeper.txn.CreateSessionTxn;
import org.apache.zookeeper.txn.ErrorTxn;
import org.apache.zookeeper.MultiTransactionRecord;
import org.apache.zookeeper.Op;
import org.apache.zookeeper.OpResult;
import org.apache.zookeeper.OpResult.CheckResult;
import org.apache.zookeeper.OpResult.CreateResult;
import org.apache.zookeeper.OpResult.DeleteResult;
import org.apache.zookeeper.OpResult.SetDataResult;
import org.apache.zookeeper.OpResult.ErrorResult;
/**
* This Request processor actually applies any transaction associated with a
* request and services any queries. It is always at the end of a
* RequestProcessor chain (hence the name), so it does not have a nextProcessor
* member.
*
* This RequestProcessor counts on ZooKeeperServer to populate the
* outstandingRequests member of ZooKeeperServer.
*/
public class FinalRequestProcessor implements RequestProcessor {
private static final Logger LOG = LoggerFactory.getLogger(FinalRequestProcessor.class);
ZooKeeperServer zks;
public FinalRequestProcessor(ZooKeeperServer zks) {
this.zks = zks;
}
public void processRequest(Request request) {
if (LOG.isDebugEnabled()) {
LOG.debug("Processing request:: " + request);
}
// request.addRQRec(">final");
long traceMask = ZooTrace.CLIENT_REQUEST_TRACE_MASK;
if (request.type == OpCode.ping) {
traceMask = ZooTrace.SERVER_PING_TRACE_MASK;
}
if (LOG.isTraceEnabled()) {
ZooTrace.logRequest(LOG, traceMask, 'E', request, "");
}
ProcessTxnResult rc = null;
synchronized (zks.outstandingChanges) {
while (!zks.outstandingChanges.isEmpty()
&& zks.outstandingChanges.get(0).zxid <= request.zxid) {
ChangeRecord cr = zks.outstandingChanges.remove(0);
if (cr.zxid < request.zxid) {
LOG.warn("Zxid outstanding "
+ cr.zxid
+ " is less than current " + request.zxid);
}
if (zks.outstandingChangesForPath.get(cr.path) == cr) {
zks.outstandingChangesForPath.remove(cr.path);
}
}
if (request.hdr != null) {
rc = zks.getZKDatabase().processTxn(request.hdr, request.txn);
if (request.type == OpCode.createSession) {
if (request.txn instanceof CreateSessionTxn) {
CreateSessionTxn cst = (CreateSessionTxn) request.txn;
zks.sessionTracker.addSession(request.sessionId, cst
.getTimeOut());
} else {
LOG.warn("*****>>>>> Got "
+ request.txn.getClass() + " "
+ request.txn.toString());
}
} else if (request.type == OpCode.closeSession) {
zks.sessionTracker.removeSession(request.sessionId);
}
}
// do not add non quorum packets to the queue.
if (Request.isQuorum(request.type)) {
zks.getZKDatabase().addCommittedProposal(request);
}
}
if (request.hdr != null && request.hdr.getType() == OpCode.closeSession) {
ServerCnxnFactory scxn = zks.getServerCnxnFactory();
// this might be possible since
// we might just be playing diffs from the leader
if (scxn != null && request.cnxn == null) {
// calling this if we have the cnxn results in the client's
// close session response being lost - we've already closed
// the session/socket here before we can send the closeSession
// in the switch block below
scxn.closeSession(request.sessionId);
return;
}
}
if (request.cnxn == null) {
return;
}
ServerCnxn cnxn = request.cnxn;
String lastOp = "NA";
zks.decInProcess();
Code err = Code.OK;
Record rsp = null;
boolean closeSession = false;
try {
if (request.hdr != null && request.hdr.getType() == OpCode.error) {
throw KeeperException.create(KeeperException.Code.get((
(ErrorTxn) request.txn).getErr()));
}
KeeperException ke = request.getException();
if (ke != null && request.type != OpCode.multi) {
throw ke;
}
if (LOG.isDebugEnabled()) {
LOG.debug("{}",request);
}
switch (request.type) {
case OpCode.ping: {
zks.serverStats().updateLatency(request.createTime);
lastOp = "PING";
cnxn.updateStatsForResponse(request.cxid, request.zxid, lastOp,
request.createTime, System.currentTimeMillis());
cnxn.sendResponse(new ReplyHeader(-2,
zks.getZKDatabase().getDataTreeLastProcessedZxid(), 0), null, "response");
return;
}
case OpCode.createSession: {
zks.serverStats().updateLatency(request.createTime);
lastOp = "SESS";
cnxn.updateStatsForResponse(request.cxid, request.zxid, lastOp,
request.createTime, System.currentTimeMillis());
zks.finishSessionInit(request.cnxn, true);
return;
}
case OpCode.multi: {
lastOp = "MULT";
rsp = new MultiResponse() ;
for (ProcessTxnResult subTxnResult : rc.multiResult) {
OpResult subResult ;
switch (subTxnResult.type) {
case OpCode.check:
subResult = new CheckResult();
break;
case OpCode.create:
subResult = new CreateResult(subTxnResult.path);
break;
case OpCode.delete:
subResult = new DeleteResult();
break;
case OpCode.setData:
subResult = new SetDataResult(subTxnResult.stat);
break;
case OpCode.error:
subResult = new ErrorResult(subTxnResult.err) ;
break;
default:
throw new IOException("Invalid type of op");
}
((MultiResponse)rsp).add(subResult);
}
break;
}
case OpCode.create: {
lastOp = "CREA";
rsp = new CreateResponse(rc.path);
err = Code.get(rc.err);
break;
}
case OpCode.delete: {
lastOp = "DELE";
err = Code.get(rc.err);
break;
}
case OpCode.setData: {
lastOp = "SETD";
rsp = new SetDataResponse(rc.stat);
err = Code.get(rc.err);
break;
}
case OpCode.setACL: {
lastOp = "SETA";
rsp = new SetACLResponse(rc.stat);
err = Code.get(rc.err);
break;
}
case OpCode.closeSession: {
lastOp = "CLOS";
closeSession = true;
err = Code.get(rc.err);
break;
}
case OpCode.sync: {
lastOp = "SYNC";
SyncRequest syncRequest = new SyncRequest();
ByteBufferInputStream.byteBuffer2Record(request.request,
syncRequest);
rsp = new SyncResponse(syncRequest.getPath());
break;
}
case OpCode.check: {
lastOp = "CHEC";
rsp = new SetDataResponse(rc.stat);
err = Code.get(rc.err);
break;
}
case OpCode.exists: {
lastOp = "EXIS";
// TODO we need to figure out the security requirement for this!
ExistsRequest existsRequest = new ExistsRequest();
ByteBufferInputStream.byteBuffer2Record(request.request,
existsRequest);
String path = existsRequest.getPath();
if (path.indexOf('\0') != -1) {
throw new KeeperException.BadArgumentsException();
}
Stat stat = zks.getZKDatabase().statNode(path, existsRequest
.getWatch() ? cnxn : null);
rsp = new ExistsResponse(stat);
break;
}
case OpCode.getData: {
lastOp = "GETD";
GetDataRequest getDataRequest = new GetDataRequest();
ByteBufferInputStream.byteBuffer2Record(request.request,
getDataRequest);
DataNode n = zks.getZKDatabase().getNode(getDataRequest.getPath());
if (n == null) {
throw new KeeperException.NoNodeException();
}
Long aclL;
synchronized(n) {
aclL = n.acl;
}
PrepRequestProcessor.checkACL(zks, zks.getZKDatabase().convertLong(aclL),
ZooDefs.Perms.READ,
request.authInfo);
Stat stat = new Stat();
byte b[] = zks.getZKDatabase().getData(getDataRequest.getPath(), stat,
getDataRequest.getWatch() ? cnxn : null);
rsp = new GetDataResponse(b, stat);
break;
}
case OpCode.setWatches: {
lastOp = "SETW";
SetWatches setWatches = new SetWatches();
// XXX We really should NOT need this!!!!
request.request.rewind();
ByteBufferInputStream.byteBuffer2Record(request.request, setWatches);
long relativeZxid = setWatches.getRelativeZxid();
zks.getZKDatabase().setWatches(relativeZxid,
setWatches.getDataWatches(),
setWatches.getExistWatches(),
setWatches.getChildWatches(), cnxn);
break;
}
case OpCode.getACL: {
lastOp = "GETA";
GetACLRequest getACLRequest = new GetACLRequest();
ByteBufferInputStream.byteBuffer2Record(request.request,
getACLRequest);
Stat stat = new Stat();
List<ACL> acl =
zks.getZKDatabase().getACL(getACLRequest.getPath(), stat);
rsp = new GetACLResponse(acl, stat);
break;
}
case OpCode.getChildren: {
lastOp = "GETC";
GetChildrenRequest getChildrenRequest = new GetChildrenRequest();
ByteBufferInputStream.byteBuffer2Record(request.request,
getChildrenRequest);
DataNode n = zks.getZKDatabase().getNode(getChildrenRequest.getPath());
if (n == null) {
throw new KeeperException.NoNodeException();
}
Long aclG;
synchronized(n) {
aclG = n.acl;
}
PrepRequestProcessor.checkACL(zks, zks.getZKDatabase().convertLong(aclG),
ZooDefs.Perms.READ,
request.authInfo);
List<String> children = zks.getZKDatabase().getChildren(
getChildrenRequest.getPath(), null, getChildrenRequest
.getWatch() ? cnxn : null);
rsp = new GetChildrenResponse(children);
break;
}
case OpCode.getChildren2: {
lastOp = "GETC";
GetChildren2Request getChildren2Request = new GetChildren2Request();
ByteBufferInputStream.byteBuffer2Record(request.request,
getChildren2Request);
Stat stat = new Stat();
DataNode n = zks.getZKDatabase().getNode(getChildren2Request.getPath());
if (n == null) {
throw new KeeperException.NoNodeException();
}
Long aclG;
synchronized(n) {
aclG = n.acl;
}
PrepRequestProcessor.checkACL(zks, zks.getZKDatabase().convertLong(aclG),
ZooDefs.Perms.READ,
request.authInfo);
List<String> children = zks.getZKDatabase().getChildren(
getChildren2Request.getPath(), stat, getChildren2Request
.getWatch() ? cnxn : null);
rsp = new GetChildren2Response(children, stat);
break;
}
}
} catch (SessionMovedException e) {
// session moved is a connection level error, we need to tear
// down the connection otw ZOOKEEPER-710 might happen
// ie client on slow follower starts to renew session, fails
// before this completes, then tries the fast follower (leader)
// and is successful, however the initial renew is then
// successfully fwd/processed by the leader and as a result
// the client and leader disagree on where the client is most
// recently attached (and therefore invalid SESSION MOVED generated)
cnxn.sendCloseSession();
return;
} catch (KeeperException e) {
err = e.code();
} catch (Exception e) {
// log at error level as we are returning a marshalling
// error to the user
LOG.error("Failed to process " + request, e);
StringBuilder sb = new StringBuilder();
ByteBuffer bb = request.request;
bb.rewind();
while (bb.hasRemaining()) {
sb.append(Integer.toHexString(bb.get() & 0xff));
}
LOG.error("Dumping request buffer: 0x" + sb.toString());
err = Code.MARSHALLINGERROR;
}
ReplyHeader hdr =
new ReplyHeader(request.cxid, request.zxid, err.intValue());
zks.serverStats().updateLatency(request.createTime);
cnxn.updateStatsForResponse(request.cxid, request.zxid, lastOp,
request.createTime, System.currentTimeMillis());
try {
cnxn.sendResponse(hdr, rsp, "response");
if (closeSession) {
cnxn.sendCloseSession();
}
} catch (IOException e) {
LOG.error("FIXMSG",e);
}
}
public void shutdown() {
// we are the final link in the chain
LOG.info("shutdown of request processor complete");
}
}