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https://issues.apache.org/jira/browse/ROL-2063?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Kohei Nozaki updated ROL-2063:
------------------------------
Attachment: ROL-2063_update1.patch
Sorry I just found a problem of my "alternative" patch. it won't eliminate the
problem with posting via BloggerAPIHandler, MetaWeblogAPIHandler or so on.
I suggest a more generic approach. a shortcoming is that it evicts all of 2nd
level caches that EclipseLink managing for everytime
JPAPersistenceStrategy#flush() is invoked so it increases cache miss and brings
some performance degradation, but it's still reasonable IMHO because Roller has
its own cache mechanism.
P.S. thanks for accepting my patches and running the project. recently I'm
really enjoying playing with Roller source code. hopefully I would keep
contribute to the project.
> NextLink appears in latest entry of permalink
> ---------------------------------------------
>
> Key: ROL-2063
> URL: https://issues.apache.org/jira/browse/ROL-2063
> Project: Apache Roller
> Issue Type: Bug
> Components: Data Model & JPA Backend
> Affects Versions: 5.1.1
> Environment: PostgreSQL 9.3.4
> Reporter: Kohei Nozaki
> Assignee: David Johnson
> Priority: Minor
> Fix For: 5.1.2
>
> Attachments: ROL-2063.patch, ROL-2063_alternative.patch,
> ROL-2063_update1.patch
>
>
> With PostgreSQL, NextLink shouldn't be appeared in latest entry of permalink,
> but sometimes it appears as the link to latest entry itself.
> The cause is precision of the column WEBLOGENTRY.PUBTIME in PostgreSQL. it is
> created with the type "timestamp(2) with time zone" as specified in
> postgresql.properties. the problem occurs as follows.
> 1. Someone posts an entry. following SQL was executed:
> 2015-02-23 17:07:26 JST LOG: execute <unnamed>: INSERT INTO weblogentry (id,
> allowcomments, anchor, commentdays, content_src, content_type, creator, link,
> locale, pinnedtomain, plugins, pubtime, righttoleft, search_description,
> status, summary, text, title, updatetime, categoryid, websiteid) VALUES ($1,
> $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14, $15, $16, $17, $18,
> $19, $20, $21)
> 2015-02-23 17:07:26 JST DETAIL: parameters: $1 =
> '71837e6f-735b-4c7e-b498-6b432accdcb2', $2 = 't', $3 = 'test', $4 = '0', $5 =
> NULL, $6 = NULL, $7 = 'kyle', $8 = NULL, $9 = 'en_US', $10 = 'f', $11 = '',
> $12 = '2015-02-23 17:07:26.548+09', $13 = 'f', $14 = '', $15 = 'PUBLISHED',
> $16 = '', $17 = 'test', $18 = 'test', $19 = '2015-02-23 17:07:26.551+09', $20
> = 'fb216817-f8ea-46ec-aad9-35d9f222cac4', $21 =
> '78d076b8-19c2-4ee0-a766-2cdaf0b75d0d'
> 2. Someone visits the permalink of the entry just posted.
> JPAWeblogEntryManager#getNextEntry() is invoked and following SQL was
> executed and the query returns a row of current latest entry itself.
> 2015-02-23 17:07:34 JST LOG: execute <unnamed>: SELECT id AS a1,
> allowcomments AS a2, anchor AS a3, commentdays AS a4, content_src AS a5,
> content_type AS a6, creator AS a7, link AS a8, lo
> cale AS a9, pinnedtomain AS a10, plugins AS a11, pubtime AS a12, righttoleft
> AS a13, search_description AS a14, status AS a15, summary AS a16, text AS
> a17, title AS a18, updatetime AS a19,
> categoryid AS a20, websiteid AS a21 FROM weblogentry WHERE (((websiteid =
> $1) AND (status = $2)) AND (pubtime > $3)) ORDER BY pubtime ASC LIMIT $4
> OFFSET $5
> 2015-02-23 17:07:34 JST DETAIL: parameters: $1 =
> '78d076b8-19c2-4ee0-a766-2cdaf0b75d0d', $2 = 'PUBLISHED', $3 = '2015-02-23
> 17:07:26.548+09', $4 = '1', $5 = '0'
> It caused by the entry of PUBTIME is stored after rounded in the table as
> follows:
> roller2=# select title, pubtime FROM weblogentry WHERE (((websiteid =
> '78d076b8-19c2-4ee0-a766-2cdaf0b75d0d') AND (status = 'PUBLISHED')) AND
> (pubtime > '2015-02-23 17:07:26.548+09')) ORDER BY pubtime ASC LIMIT '1'
> OFFSET '0';
> title | pubtime
> -------+---------------------------
> test | 2015-02-23 17:07:26.55+09
> (1 row)
> Roller compared '2015-02-23 17:07:26.548+09' against '2015-02-23
> 17:07:26.55+09' and recognized current latest entry itself as next entry
> while PUBTIME was rounded '.548' to '.55'. I don't know where Roller keeps
> '2015-02-23 17:07:26.548+09' but I guess that it saved in caches in Roller or
> EclipseLink because restarting of application server solves the problem
> temporarily.
> To solve the problem, I think changing precision of TIMESTAMP_SQL_TYPE_NULL
> and TIMESTAMP_SQL_TYPE in /resources/sql/postgresql.properties from 2 to 3 is
> reasonable because Roller uses milliseconds precision with java.util.Date,
> larger precision is unnecessary though.
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