With Ehcache and spring what happens if a load balanced server become unavailable? -

-

i'm working on web app ehcache deployed. app load balanced between multiple servers. app installed on each server , when user accesses app he/she redirected 1 of load balanced servers.

is understanding of following correct? if user makes request key , it's annotated @cacheable check made value in ehcache store. if key in store value returned ehcache, if key not in store key , value added store , value returned. if 1 of load balanced servers becomes unavailable , user requests value has been cached in now-unavailable server new value added cache store , returned user described above.

there no risk of user requesting key not available, there?

i don't understand mean a key not available.

essentially, spring caching abstraction works more or less described. spring delegates actual caching business configured caching library. in case, ehcache.

if have 1 cache per node, each node have copy of data. if 1 server goes down , user requests not yet in server's store, put in node's store described.

if have distributed cache, fact server goes down meaningless regards question: cached data still available other node.

in case, cacheable tries retrieve value cache before calling method , returns directly in case of cache hit. in case of cache miss, method executed , result stored in cache.


Comments

Post a Comment

Popular posts from this blog

c# - How to get the current UAC mode -

-
can check current uac type set in device before running application through c#. i got know approach check whether current user administrator or not. but, need know uac type set (i.e. default/never notify) internal logic. is possible? please help. this article self-elevation , checking level program runs in. due security reasons i'm afraid won't able retrieve uac level set. http://code.msdn.microsoft.com/windowsdesktop/csuacselfelevation-644673d3
Read more

postgresql - Lazarus + Postgres: incomplete startup packet -

-
i've been building lazarus pascal program using postgresql on back-end. used work fine following lines opening db. dbconn:= tpqconnection.create(nil); dbconn.hostname := 'localhost'; dbconn.databasename:= 'dbhrs'; dbconn.username:='mizk'; dbconn.password:='123'; dbconn.open; if dbconn.connected openhrsdb := true else openhrsdb := false; but moment change localhost server's ip (on lan), program stops. no errors or warnings. have no clue happening. here related details may narrow down problem. the program i'm running workstation on same lan server. both machines run ubuntu 12.04 desktop i can access postgres db on server using pgadmin iii, guess it's not firewall issue. i have allowed postgresql ufw , ufw disabled. strangely, when firewall disabled, can ssh server terminal using workstation. when it's enabled, can't my biggest concern right why pascal program not working when i...
Read more

javascript - Ajax jqXHR.status==0 fix error -

-
$.ajax({ url: urlstring, datatype: "json", type: "get", success: function (data) { alert(data); }, error: function (jqxhr, exception) { if (jqxhr.status === 0) { alert('not connect.\n verify network.'); } else if (jqxhr.status == 404) { alert('requested page not found. [404]'); } else if (jqxhr.status == 500) { alert('internal server error [500].'); } else if (exception === 'parsererror') { alert('requested json parse failed.'); } else if (exception === 'timeout') { alert('time out error.'); } else if (exception === 'abort') { alert('ajax request aborted.'); } else { alert('uncaught error.\n' + jqxhr.responsete...
Read more