<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Stefan, <div>Thanks for opening this thread here. I'm not actually doing anything like this, but it's great to see you pushing the envelop. I have done a lot of work on replicated data, over the years, that's where the following comment comes from.</div><div><br><div><div>On 22 May 2008, at 10:36, Stefan H. Holek wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">We have put up two boxes in a MySQL master-master replication setup [1]. As long as we only write to one of the masters all is fine. Writing to both masters (and expecting MySQL to sort it out) is giving us trouble. We see things like:<br><br>Last_Errno: 1062<br>Last_Error: Error 'Duplicate entry '41860' for key 1' on query.<br>Default database: 'prod_zodb'.<br>Query: 'INSERT INTO new_oid VALUES ()'</blockquote><div>I have not read the reference, but it seems that this scheme can never work without keys (OIDs) being qualified by which master they originated on. Otherwise one of the mySQLs would need to be responsible for handing out unique oids. You need an OID origination namespace for each master. </div><div><br></div><div>On the other issue, no idea.</div><div><br></div><div>Best,</div><div><br></div><div>--r.</div><br><blockquote type="cite"><br><br>and<br><br>Last_Errno: 1050<br>Last_Error: Error 'Table 'temp_store' already exists' on query.<br>Default database: 'prod_zodb'.<br>Query: 'CREATE TEMPORARY TABLE temp_store<br> (<br> zoid BIGINT NOT NULL PRIMARY KEY,<br> prev_tid BIGINT NOT NULL,<br> md5 CHAR(32),<br> state LONGBLOB<br> ) ENGINE MyISAM'<br><br>Stefan<br><br>[1] <a href="http://www.howtoforge.com/mysql_master_master_replication">http://www.howtoforge.com/mysql_master_master_replication</a><br><br><br>On 20.05.2008, at 18:36, Shane Hathaway wrote:<br><br><blockquote type="cite">That is mostly correct. You need to replicate transaction, object_state, current_object, and do something with new_oid. There is no requirement to replicate the other tables, since they are used only for packing, although replicating object_ref and object_refs_added may save some work.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">The new_oid table is special to the MySQL adapter. RelStorage uses the new_oid table as a kind of sequence. Like any sequence, it is intentionally non-transactional. Perhaps there would be no ill effects in switching it to the InnoDB engine.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Which MySQL replication method are you looking into?<br></blockquote><br>--<br>Stefan H. Holek<br><a href="mailto:stefan@epy.co.at">stefan@epy.co.at</a><br><br>_______________________________________________<br>For more information about ZODB, see the ZODB Wiki:<br>http://www.zope.org/Wikis/ZODB/<br><br>ZODB-Dev mailing list - ZODB-Dev@zope.org<br>http://mail.zope.org/mailman/listinfo/zodb-dev<br></blockquote></div><br><div> <span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Verdana; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; color: rgb(0, 0, 0); font-family: Verdana; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; -webkit-text-decorations-in-effect: none; text-indent: 0px; -webkit-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div id="sig" style="line-height: 13px; margin-top: 4px; margin-right: 0px; margin-bottom: 4px; margin-left: 0px; padding-top: 2px; padding-right: 4px; padding-bottom: 2px; padding-left: 4px; font-family: Verdana, Arial, Helvetica, sans-serif; font-weight: bold; font-size: 10px; color: black; "><div style="float: left; padding-top: 2px; padding-right: 6px; padding-bottom: 2px; padding-left: 6px; background-color: rgb(238, 238, 238); font-size: 10px; font-weight: bold; line-height: 13px; "><strong style="font-size: 10px; font-weight: bold; line-height: 13px; "><span class="Apple-style-span" style="font-size: 10px; font-weight: bold; line-height: 13px; ">Russ Ferriday</span></strong><span class="Apple-style-span" style="font-size: 10px; font-weight: bold; line-height: 13px; "><span class="Apple-converted-space"> </span>-<span class="Apple-converted-space"> </span></span><a href="http://topia.com/" title="visit topia.com" style="text-decoration: none; color: rgb(102, 102, 102); font-size: 10px; font-weight: bold; line-height: 13px; "><span class="Apple-style-span" style="color: rgb(102, 102, 102); font-size: 10px; font-weight: bold; line-height: 13px; ">Topia Systems</span></a><span class="Apple-style-span" style="font-size: 10px; font-weight: bold; line-height: 13px; "><span class="Apple-converted-space"> </span>- Open Source content management with Plone and Zope</span><br style="font-size: 10px; font-weight: bold; line-height: 13px; "><a href="mailto:russf@topia.com" style="text-decoration: none; color: rgb(102, 102, 102); font-size: 10px; font-weight: bold; line-height: 13px; "><span class="Apple-style-span" style="color: rgb(102, 102, 102); font-size: 10px; font-weight: bold; line-height: 13px; ">russf@topia.com</span></a><span class="Apple-style-span" style="font-size: 10px; font-weight: bold; line-height: 13px; "><span class="Apple-converted-space"> </span>- office: +44 2076 1777588 - mobile: +44 7789 338868 - skype: ferriday</span></div></div></div></span></div></span> </div><br></div></body></html>