zookeeper是hbase集群的"协调器"。由于zookeeper的轻量级特性,因此我们可以将多个hbase集群共用一个zookeeper集群,以节约大量的服务器。多个hbase集群共用zookeeper集群的方法是使用同一组ip,修改不同hbase集群的"zookeeper.znode.parent"属性,让它们使用不同的根目录。比如cluster1使用/hbase-c1,cluster2使用/hbase-c2,等等。
使用以上方法有一个现实的问题:如何避免各集群的相互干扰?因为client的配置权是在用户手上,并不能保证用户永远是配置正确的,那么会产生某个用户访问了不该他访问的hbase集群。此时数据安全性成了很大的问题,甚至可能出现误删除数据。我们需要在zookeeper层屏弊掉该问题。
zookeeper3.x版本起自带了简单的ACL功能(注意3.3.x版本起不再支持按hostname来分配权限)。见:http://zookeeper.apache.org/doc/r3.3.2/zookeeperProgrammers.html#sc_ZooKeeperAccessControl。进行权限配置主要使用digest和ip两种方法。其中digest是用户密码方式,对用户来说使用上并不透明。ip配置最简单,对用户也是透明的,用户并不知道的情况下就能限制它的访问权限。
zookeeper将访问权限分为了五类:READ/WRITE/DELETE/CREATE/ADMIN,其中admin为最高权限。zookeeper的权限是到znode级别的,限制了某一个node的权限并不能限制它的子节点权限。
不过使用IP做权限配置方案有一个缺陷:必须指定具体的ip,而不能使用通配符或者范围一类的。这样对于大规模的权限设置是非常不方便的一件事,因此作者略调整了一下zookeeper的代码:
IPAuthenticationProvider.java
- /**
- * 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.auth;
- import org.apache.zookeeper.data.Id;
- import org.apache.zookeeper.server.ServerCnxn;
- import org.apache.zookeeper.KeeperException;
- public class IPAuthenticationProvider implements AuthenticationProvider {
- public String getScheme() {
- return "ip";
- }
- public KeeperException.Code
- handleAuthentication(ServerCnxn cnxn, byte[] authData)
- {
- String id = cnxn.getRemoteAddress().getAddress().getHostAddress();
- cnxn.getAuthInfo().add(new Id(getScheme(), id));
- return KeeperException.Code.OK;
- }
- // This is a bit weird but we need to return the address and the number of
- // bytes (to distinguish between IPv4 and IPv6
- private byte[] addr2Bytes(String addr) {
- byte b[] = v4addr2Bytes1(addr);
- // TODO Write the v6addr2Bytes
- return b;
- }
- private byte v4addr2Bytes(String part) throws NumberFormatException{
- try {
- int v = Integer.parseInt(part);
- if (v >= 0 && v <= 255) {
- byte b = (byte) v;
- return b;
- } else {
- throw new NumberFormatException("v < 0 or v > 255!");
- }
- } catch (NumberFormatException e) {
- throw e;
- }
- }
- private byte[] v4addr2Bytes1(String addr) {
- String parts[] = addr.split("\\.", -1);
- if (parts.length != 4) {
- return null;
- }
- byte b[] = new byte[4];
- for (int i = 0; i < 4; i++) {
- try {
- if(parts[i].split("/").length == 2){
- v4addr2Bytes(parts[i].split("/")[0]);
- v4addr2Bytes(parts[i].split("/")[1]);
- continue;
- }else{
- b[i] = v4addr2Bytes(parts[i]);
- }
- } catch (NumberFormatException e) {
- return null;
- }
- }
- return b;
- }
- public boolean matches(String id, String aclExpr) {
- String parts[] = aclExpr.split("/", 2);
- byte aclAddr[] = addr2Bytes(parts[0]);
- if (aclAddr == null) {
- return false;
- }
- byte endAclAddr[] = new byte[aclAddr.length];
- for(int i = 0; i < aclAddr.length; i ++){
- endAclAddr[i] = aclAddr[i];
- }
- if (parts.length == 2) {
- try {
- int end = Integer.parseInt(parts[1]);
- int e = endAclAddr[endAclAddr.length-1]<=0?endAclAddr[endAclAddr.length-1]+256:endAclAddr[endAclAddr.length-1];
- if(end < e|| end < 0 || end > 255)
- return false;
- endAclAddr[endAclAddr.length-1] = (byte)end;
- } catch (NumberFormatException e) {
- return false;
- }
- }
- byte remoteAddr[] = addr2Bytes(id);
- if (remoteAddr == null) {
- return false;
- }
- for (int i = 0; i < remoteAddr.length; i++) {
- int r = remoteAddr[i]<=0?(int)remoteAddr[i]+256:remoteAddr[i];
- int a = aclAddr[i]<=0?(int)aclAddr[i]+256:aclAddr[i];
- int e = endAclAddr[i]<=0?(int)endAclAddr[i]+256:endAclAddr[i];
- if (r < a || r > e) {
- return false;
- }
- }
- return true;
- }
- public boolean isAuthenticated() {
- return false;
- }
- public boolean isValid(String id) {
- return addr2Bytes(id) != null;
- }
- }
支持了使用/做为范围标识,比如进入hbase zkcli,执行:setAcl /test ip:192.168.0.3/10:cd,则将读写权限赋给了192.168.0.3-192.168.0.10这8台机器,其它机器将没有任何权限。
这样用同一个zookeeper管理多个集群、海量机器将不再有困扰。
最后写了一个帮助运维同学自动化管理zookeeper集群下多个hbase集群的ACL权限的工具,像以下这样:
- java -Djava.ext.dirs=libs/ -cp hbase-tools.jar dwbasis.hbase.tools.client.ZookeeperAcl aclFile.json
- Usage: ZookeeperAcl acljsonfile [-plan]
- /test/t ==> 'ip,'192.168.0.1
- :cdrwa
- /test ==> 'ip,'192.168.0.1/3
- :cdrwa
- /test ==> 'ip,'192.168.0.5
- :cdrwa
- do you really setAcl as above?(y/n)
补充:多集群共用zk后,每个集群的启动和停止不应该影响zk的稳定。因此请配置hbase-env.sh中export HBASE_MANAGES_ZK=false