public GroupYedis(GroupConfig groupConfig) {
this.groupConfig = groupConfig;
msHolder.master = new Yedis(groupConfig.getMasterAtomConfig());
msHolder.slaves = createYedis(groupConfig.getSlaveAtomConfigs());
msHolder.loadBalancer = createLoadBalancer(msHolder.slaves, groupConfig.getLoadBalancerType());
this.groupConfig.addListener(this);
}
@Override
public synchronized void onChanged(MasterSlaveConfigManager configManager) {
// 如果已经关闭，则忽略配置变更
if (shutdown.get()) {
return;
}
MsHolder newMsHolder = new MsHolder();
Yedis unusedMaster = null;
List<Yedis> unusedSlaves = null;
try {
// 处理master的变化
try {
AtomConfig masterConfig = groupConfig.getMasterAtomConfig();
if (!msHolder.master.getConfig().getServerInfo().equals(masterConfig.getServerInfo())) {
newMsHolder.master = new Yedis(groupConfig.getMasterAtomConfig());
logger.info(
"Master changed to "
+ groupConfig.getMasterAtomConfig().getHost()
+ ":"
+ groupConfig.getMasterAtomConfig().getPort());
unusedMaster = msHolder.master;
} else {
newMsHolder.master = msHolder.master;
}
} catch (Exception e) {
// 如果有异常，则需要关闭刚才新建的实例
unusedMaster = newMsHolder.master;
throw e;
}
// 处理slave的变化:构造slaves，从已有yedis中复用，最后，没被复用的则close
List<Yedis> createdSlaves = new ArrayList<Yedis>();
try {
List<AtomConfig> slaveConfigs = groupConfig.getSlaveAtomConfigs();
if (slaveConfigs != null) {
List<Yedis> oldSlaves = new ArrayList<Yedis>(msHolder.slaves);
List<Yedis> newSlaves = new ArrayList<Yedis>(slaveConfigs.size());
for (AtomConfig config : slaveConfigs) {
Yedis existsYedis = takeSlaveIfExists(oldSlaves, config.getServerInfo());
if (existsYedis != null) {
// 复用已经存在的Yedis
newSlaves.add(existsYedis);
} else {
// 是新的server，则构建Yedis
Yedis yedis = new Yedis(config);
newSlaves.add(yedis);
createdSlaves.add(yedis);
logger.info(
"New slave created: "
+ yedis.getConfig().getHost()
+ ":"
+ yedis.getConfig().getPort());
}
}
newMsHolder.loadBalancer =
createLoadBalancer(newSlaves, groupConfig.getLoadBalancerType());
newMsHolder.slaves = newSlaves;
unusedSlaves = oldSlaves;
}
} catch (Exception e) {
// 如果有异常，则需要关闭刚才新建的实例
unusedSlaves = createdSlaves;
throw e;
}
// 切换
this.msHolder = newMsHolder;
} catch (Exception e) {
logger.error(
"Master/slave Config changed, but error occurred, so GroupYedis haven't switched connection: ",
e);
}
// 释放无用的yedis
if (unusedMaster != null) {
unusedMaster.close();
logger.info(
"Unused master closed: "
+ unusedMaster.getConfig().getHost()
+ ":"
+ unusedMaster.getConfig().getPort());
}
if (unusedSlaves != null) {
for (Yedis yedis : unusedSlaves) {
yedis.close();
logger.info(
"Unused slave closed: "
+ yedis.getConfig().getHost()
+ ":"
+ yedis.getConfig().getPort());
}
}
}