redis的failover ,redmon安装

midea2

redmon安装
http://www.cr173.com/html/14775_1.html
failover
参考一点http://dmouse.iyunv.com/blog/813026
redis支持master-slave模式，可以设置一个master，多个slave；采用读写分离的策略，master负责写数据，多个slave负责读数据，slave的数据是复制master上的，所以多个slave之间的数据是可以保持一致的，即便down了之后，也会通过加载dump数据的方式，重新加载会原来的缓存数据。
Fail-Tolerance
当前项目需要保证一个client连接到slave服务上读取数据，如果slave down 了之后，可以在不影响应用的情况下，自动切换到另外一个可用的slave
因为jredis不支持设置多个slave服务器，所以写了一个小工具类，目的是为了探测如果的当前正在使用的slave没有heartbeat之后，立马可以切换到一个可用的slave；这样可以保证one of slave down掉之后，不用missing-load也可及时切换到另外一个slave上读数据。

public class RedisFailToleranceUtil {
private static JRedisService jredisService =  null;
private static ConnectionSpec defaultConnectionSpec = null;
private static int current = 1;
private static HashMap<String,ConnectionSpec> serverPools = new HashMap<String,ConnectionSpec>();
static{
ConnectionSpec connectionSpec1 = DefaultConnectionSpec.newSpec("192.168.1.238", 6380, 0,null);
ConnectionSpec connectionSpec2 = DefaultConnectionSpec.newSpec("192.168.1.238", 6381, 0,null);
serverPools.put("1", connectionSpec1);
serverPools.put("2", connectionSpec2);
}
private String next(){
if(current>serverPools.size()){
current=1;
}
int nextIndex = current;
current++;
return nextIndex+"";
}
private ConnectionSpec getConnectionSpec(){
if(defaultConnectionSpec != null){
return defaultConnectionSpec;
}
jredisService = null;
/**
* we are working multiple servers
* try different servers,util we fetch the first available server pool
*/
HashMap<String,ConnectionSpec> tryServers = new HashMap<String,ConnectionSpec>(serverPools);
if(serverPools.size() == 1){
return (ConnectionSpec)serverPools.get("1");
}
while(!tryServers.isEmpty()){
ConnectionSpec connectionSpec = tryServers.get(this.next());
if(isConnect(connectionSpec)){
return connectionSpec;
}
tryServers.remove(connectionSpec);
if(tryServers.isEmpty()){
break;
}
}
return null;
}
/**
* try whether the server is available
* @param connectionSpec
* @return true or false
*/
private boolean isConnect(ConnectionSpec connectionSpec){
if(connectionSpec == null){
return false;
}
JRedis jredis = new JRedisClient(connectionSpec.getAddress().getHostAddress(), connectionSpec.getPort());
try{
jredis.ping();
jredis.quit();
}catch(Exception e){
return false;
}
return true;
}
public void initialize(){
defaultConnectionSpec = this.getConnectionSpec();
if(jredisService == null){
synchronized (RedisFailToleranceUtil.class) {
jredisService = new JRedisService(defaultConnectionSpec,100);
}
}
}

public String getS(String key){
this.initialize();
String value = null;
try {
value = DefaultCodec.toStr(jredisService.get(key));
} catch (Exception e) {
defaultConnectionSpec = null;
this.initialize();
}
return value;
}
public static void main(String args[]){
RedisFailToleranceUtil redis = new RedisFailToleranceUtil();
redis.getS("name");
try {
Thread.sleep(10000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
redis.getS("name");
try {
Thread.sleep(30000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
redis.getS("name");
}
}
改成jedis的

public class JedisPoolTest extends Assert {
private static HostAndPort hnp = HostAndPortUtil.getRedisServers().get(0);
private static HostAndPort hnp2 = HostAndPortUtil.getRedisServers().get(1);
private static HashMap<String,JedisPool> serverPools = new HashMap<String,JedisPool>();
static{
JedisPool pool1 = new JedisPool(new JedisPoolConfig(), hnp.host, hnp.port, 2000);
JedisPool pool2 = new JedisPool(new JedisPoolConfig(), hnp2.host, hnp2.port, 2000);
serverPools.put("1", pool1);
serverPools.put("2", pool2);
}
private static int current = 1;
static Jedis jredisService=null;
private static JedisPool defaultConnectionSpec = null;
public void initialize(){
defaultConnectionSpec = this.getConnectionSpec();
if(jredisService == null){
synchronized (RedisFailToleranceUtil.class) {
jredisService = defaultConnectionSpec.getResource();
}
}
}
public String getS(String key){
this.initialize();
String value = null;
try {
value = jredisService.get(key);
} catch (Exception e) {
defaultConnectionSpec = null;
this.initialize();
}
return value;
}
public static void main(String[] args) {
JedisPoolTest redis = new JedisPoolTest();
System.out.println("1 "+redis.getS("foo"));
try {
Thread.sleep(10000);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("2  "+redis.getS("foo"));
try {
Thread.sleep(10000);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("3  "+redis.getS("foo"));
try {
Thread.sleep(10000);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("4  "+redis.getS("foo"));
try {
Thread.sleep(10000);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("5  "+redis.getS("foo"));
}
private JedisPool getConnectionSpec(){
if(defaultConnectionSpec != null){
return defaultConnectionSpec;
}
HashMap<String,JedisPool> tryServers = new HashMap<String,JedisPool>(serverPools);
System.out.println("tryServers:"+tryServers.size());
if(serverPools.size() == 1){
System.out.println("22222");
//jredisService=connectionSpec.getResource();
return (JedisPool)serverPools.get("2");
}
while(!tryServers.isEmpty()){
JedisPool connectionSpec = tryServers.get("1");
if(isConnect(connectionSpec)){
System.out.println("1111");
jredisService=connectionSpec.getResource();
return connectionSpec;
}else{
connectionSpec = tryServers.get("2");
jredisService=connectionSpec.getResource();
System.out.println("1111---2222");
serverPools.remove("1");
return connectionSpec;
}
}
return null;
}
private boolean isConnect(JedisPool pool){
if(pool == null){
return false;
}
try{
Jedis jedis = pool.getResource();
jedis.ping();
pool.returnResource(jedis);
}catch(Exception e){
return false;
}
return true;
}
}
----------------
安装
jredis
https://github.com/alphazero/jredis/downloads
http://liuxinglanyue.iyunv.com/blog/829428
参数说明
http://aronlulu.iyunv.com/blog/1236773
appendonly
默认情况下，redis 会在后台异步的把数据库镜像备份到磁盘，但是该备份是非常耗时
的，而且备份也不能很频繁，如果发生诸如拉闸限电、拔插头等状况，那么将造成比较
大范围的数据丢失。所以 redis提供了另外一种更加高效的数据库备份及灾难恢复方式。
开启 append only 模式之后，redis 会把所接收到的每一次写操作请求都追加到
appendonly.aof 文件中，当redis重新启动时，会从该文件恢复出之前的状态。但是这样
会造成 appendonly.aof 文件过大，所以 redis 还支持了 BGREWRITEAOF 指令，对
appendonly.aof 进行重新整理。所以我认为推荐生产环境下的做法为关闭镜像，开启
appendonly.aof，同时可以选择在访问较少的时间每天对 appendonly.aof 进行重写一次

注意dump.rdb文件
默认在redis-server的同一个目录下
dir指定
官方文档
http://try.redis-db.com/
导出json
https://github.com/delano/redis-dump
--------------
rais的安装
http://archive.cnblogs.com/a/1937602/
http://www.cnblogs.com/watir/archive/2011/01/17/1937602.html
为了装https://github.com/steelThread/redmon
redmon
sqlite3报错
http://blog.toolib.net/cnmahj/2011/09/rails3-1%E4%BD%BF%E7%94%A8sqlite%E6%97%B6%E2%80%9Csqlite3_int64-undeclared%E2%80%9D%E9%94%99%E8%AF%AF%E7%9A%84%E8%A7%A3%E5%86%B3%E6%96%B9%E6%B3%95/

i容量预计和估算
http://blog.nosqlfan.com/html/3430.html
u不过发现脚本执行几次，差值不一样
数据增量存储
http://www.hoterran.info/redis_persistence
源码分析
http://blog.nosqlfan.com/html/2949.html?ref=rediszt
资料总会专题
http://blog.nosqlfan.com/html/3537.html
Redis采用不同内存分配器碎片率对比
http://blog.nosqlfan.com/html/3490.html
目录
http://blog.nosqlfan.com/tags/redis
Redis复制与可扩展集群搭建
http://www.infoq.com/cn/articles/tq-redis-copy-build-scalable-cluster
测试，需要看valgrind
http://blog.nosqlfan.com/html/2383.html
容量
http://timyang.net/data/redis-capacity/
微波两个人
http://weibo.com/bachmozart?key_word=redis
http://weibo.com/tangfl?key_word=redis
lua
http://blog.nosqlfan.com/html/1658.html
ruby的监控
用最新版zlib问题
https://rvm.beginrescueend.com/rvm/install/
http://belmount.blog.iyunv.com/1897431/766728
https://blog.johncheng.com/?p=1389
rvm
http://floger.iyunv.com/blog/935374

不用openssl
最后那个运行下就行
rvm requirements
rvm install 1.9.3
rvm list
rvm alias create default ruby-1.9.3-p125
gem install bundler
rvm rubygems latest
rvm pkg install openssl
gem install rails
rvm gemset list
看rails的版本，然后
rvm gemset create rails3.2.1

rvm pkg install zlib ;
rvm pkg install readline;
rvm pkg install openssl;
rvm pkg install iconv;
rvm remove 1.9.3;
rvm install 1.9.3 --with-zlib-dir=$rvm_path/usr --with-openssl-dir=$rvm_path/usr --with-readline-dir=$rvm_path/usr --with-iconv-dir=$rvm_path/usr
rvm gemset create rails3.2.1
zlib
https://rvm.beginrescueend.com/packages/zlib/
Ruby 1.9.3-p0 makes psych—the replacement for 1.8.7’s YAML library,
http://www.cnblogs.com/qq78292959/archive/2011/12/15/2288567.html
rvm info
rvm requirements
rvm install 1.8.7
rvm list
rvm alias create default ruby-1.8.7-p358
ruby -v
gem install rails
rvm gemset list
rvm gemset list
rvm gemset create rails3.2.1
gem install jquery-rails
rails new demo1
集群
http://wenku.baidu.com/view/d9ac5ab9960590c69ec37683.html
cassandra
http://baike.baidu.com/view/1350234.htm
2.6 Redis集群功能说明
http://blog.nosqlfan.com/html/3302.html
ppt
http://blog.nosqlfan.com/html/1007.html
hash
http://emreyilmaz.me/implementing-consistent-hashing-into-your-redis