id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	due_date
121	20141009升级Memcache遇到的问题及解决	luoyongmin		"升级Memcache步骤见附件：IT商城memcache升级.txt
1、升级后发现编辑报障有个别商情页有报错。
2、查看memcache使用概况。登陆memcache所在服务器，使用命令xmem参看。
未发现memcache异常
3、查看应用日志
发现有memcache异常信息，stderr_m.pconline.log：
[10-09 14:24:32.841] 13404745 [http-m.pconline-8082-39] ERROR com.danga.MemCached.MemCachedClient - ++++ exception thrown while trying to get object from cache for key: /company_price_new.jsp?productID=558826&area=全国&pageSize=20&pageNo=1&part=2
[10-09 14:24:32.841] 13404745 [http-m.pconline-8082-39] ERROR com.danga.MemCached.MemCachedClient - MemcachedClient Error! Expect key:/company_price_new.jsp?productID=558826&area=全国&pageSize=20&pageNo=1&part=2, but return key: /company_price_new.jsp?productID=558826&area=??????ú&pageSize=20&pageNo=1&part=2
[10-09 14:24:32.841] java.lang.RuntimeException: MemcachedClient Error! Expect key:/company_price_new.jsp?productID=558826&area=全国&pageSize=20&pageNo=1&part=2, but return key: /company_price_new.jsp?productID=558826&area=??????ú&pageSize=20&pageNo=1&part=2
[10-09 14:24:32.843] 	at com.schooner.MemCached.AscIIClient.get(AscIIClient.java:735)
[10-09 14:24:32.843] 	at com.schooner.MemCached.AscIIClient.get(AscIIClient.java:630)
[10-09 14:24:32.843] 	at com.schooner.MemCached.AscIIClient.get(AscIIClient.java:626)
[10-09 14:24:32.843] 	at com.danga.MemCached.MemCachedClient.get(MemCachedClient.java:1094)
[10-09 14:24:32.843] 	at cn.com.pconline.enterprise.web.tag.CacheTag.doStartTag(CacheTag.java:372)
[10-09 14:24:32.843] 	at _jsp._yp._company_0price__jsp._jspService(_company_0price__jsp.java:1079)
4、判断是memcache对特殊字符处理出错
5、修复
修改CacheTag.java，对缓存key进行md5转换[key = cn.com.pconline.enterprise.util.MD5.compute(key)]
6、结果
经过md5转换后的key不再抛出异常

总结：
升级memcache要注意key的不同处理方式的兼容性。升级后留意观察日志。"	task	new	major	2012年6.0版本	商家后台	6.0		Memcache		10/10/2014