Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Plain View
Zookeeper, mail # user - Error in zookeeper recipes documention of " Leader Election"


Copy link to this message
-
Error in zookeeper recipes documention of " Leader Election"
nileader 2012-09-11, 01:13
Hi,all

   About “Leader Election”part of zookeeper recipes documention(
http://zookeeper.apache.org/doc/trunk/recipes.html#sc_leaderElection),many
of my colleagues are confused on this: "Otherwise, watch for changes on
"ELECTION/guid-n_j", where j is the smallest sequence number such that j <
i and n_j is a znode in C;"

   In my course, I tell them that in this using case, just watch the node
that only smaller than you, And the meaning of the expression here is
inconsistent.

   I think the document is error。
*nileader* ni掌櫃的個人郵箱
*MSN*: [EMAIL PROTECTED]
*Weibo*:http://weibo.com/nileader
————————————————————————————————————————————————————————————————————————
This email (including any attachments) is confidential and may be legally
privileged, private information of correct recipient and nileader. If you
received this email in error, please delete it immediately and do not copy
it or use it for any purpose or disclose its contents to any other person.
Thank you.
*
本電郵(包括任何附件)可能含有機密資料並受法律保護,屬於ni掌櫃和正確收件人之間的私有信息。如您不是正確的收件人,請您立即刪除本郵件。請不要將本電郵進行複製並用作任何其它用途,或透露本郵件之內容。謝謝。
*

2012/9/8 Ben Bangert <[EMAIL PROTECTED]>

> As I was implementing read-only mode in the Python client based on the
> Java client patch, I noticed a rather odd naming for the error you get if
> you send a modification command to a read-only
> server...NotReadOnlyException.
>
> Why the sudden change in error context?
>
> For reference, here's some of the other errors that Zookeeper may return
> when making an API call:
> NoNode
> NoAuth
> BadVersion
> NoChildrenForEphemerals
> NodeExists
> NotEmpty
>
> So the explanation for these errors are consistent, "your API call cannot
> be completed because of this state on the server". Personally, I'm a huge
> fan of consistency in an API, so these are all great. But then with
> NotReadOnly, we have an error that is not referring to the state of the
> server (that it *is* ReadOnly), but one that refers to the semantics of the
> API call itself. Given all the other errors, I was really expecting the
> server to throw a ReadOnly error indicating your call cannot be completed
> due to that state on the server (like the others).
>
> Was there a reason for the context switch in error naming? I understand
> given its been merged in for almost 2 years now that there's unlikely to be
> any switch to make it consistent in context with the other errors, but it
> might be nice for future feature additions to try and document or enforce
> better consistency in the API.
>
> Cheers,
> Ben
+
Ishaaq Chandy 2012-09-11, 01:26
+
Michi Mutsuzaki 2012-09-11, 01:45