Author: arminw
Date: Thu Aug 17 09:16:56 2006
New Revision: 432277
URL: http://svn.apache.org/viewvc?rev=432277&view=rev
Log:
improve frequently errors section
Modified:
db/ojb/branches/OJB_1_0_RELEASE/src/doc/forrest/src/documentation/content/xdocs/docu/faq.xml
Modified:
db/ojb/branches/OJB_1_0_RELEASE/src/doc/forrest/src/documentation/content/xdocs/docu/faq.xml
URL:
http://svn.apache.org/viewvc/db/ojb/branches/OJB_1_0_RELEASE/src/doc/forrest/src/documentation/content/xdocs/docu/faq.xml?rev=432277&r1=432276&r2=432277&view=diff
==============================================================================
---
db/ojb/branches/OJB_1_0_RELEASE/src/doc/forrest/src/documentation/content/xdocs/docu/faq.xml
(original)
+++
db/ojb/branches/OJB_1_0_RELEASE/src/doc/forrest/src/documentation/content/xdocs/docu/faq.xml
Thu Aug 17 09:16:56 2006
@@ -455,92 +455,139 @@
</p>
</answer>
</faq>
+ </faqsection>
+ <faqsection id="mistakes">
+ <title>Beginner's mistakes: Frequently error logs and problems</title>
- <faqsection id="mistakes">
- <title>Beginner's mistakes: Frequently error logs</title>
-
- <faq id="generalRecommendations">
- <question>
- General recommendations for all errors
- </question>
- <answer>
- <p>
- Please search the whole stack trace and all logging
output to find
- the reason of the error.
- </p>
- <note>
- General recommendations:
- <br/>
- - Search for error and warn messages in logged before
exception stack trace.
- <br/>
- - Try to find the <em>root exception</em> causing the
error (OJB normally wraps
- exceptions).
- </note>
- </answer>
- </faq>
-
- <faq id="couldNotBorrowConnection">
+ <faq id="generalRecommendations">
<question>
- Error message: <em>Could not borrow connection from pool</em>
+ General recommendations for all errors
</question>
<answer>
- <ul>
- <li>
- Connection pool is exhausted, because pool size is too
low or the database
- maximum connection limit is reached.
- </li>
- <li>
- Jdbc-Driver issues (wrong arguments, classpath issues,
missing driver jar, ...).
- </li>
- <li>
- Specified <em>validation query</em> (in
- <a
href="site:repository/jdbc-connection-descriptor">jdbc-connection-descriptor</a>)
- cause an error.
- </li>
- <li>
- Too many concurrent threads exhaust connection pool.
- </li>
- <li>
- Persistence broker <a
href="site:pb-guide/detect-leak">leak</a>.
- </li>
- </ul>
+ <p>
+ Please search the whole stack trace and all logging output
to find
+ the reason of the error.
+ </p>
+ <note>
+ General recommendations:
+ <br/>
+ - Search for error and warn messages in logging output
before
+ the exception (stack trace) occur.
+ <br/>
+ - Try to find the <em>root exception</em> causing the
error (OJB normally wraps
+ exceptions).
+ </note>
</answer>
- </faq>
+ </faq>
- <faq id="couldNotBorrowBroker">
+ <faq id="loadConfiguration">
<question>
- Error message: <em>Borrow broker from pool failed,...</em>.
+ OJB cannot load configuration files: OJB.properties,
repository.xml, ...?
</question>
<answer>
- <ul>
- <li>
- <code>PersistenceBroker</code> instance pool is
exhausted, because pool size is too
- low or too many concurrent threads exhaust connection
pool.
- </li>
- <li>
- Persistence broker <a
href="site:pb-guide/detect-leak">leak</a>, missing
- <code>PersistenceBroker.close()</code> calls.
- </li>
- </ul>
+ <p>
+ For web applications: put all OJB configuration files into
WEB-INF/classes.
+ <br/>
+ For other applications: put the config files into your
classpath root.
+ <br/>
+ More details about hoe to bundle files can be found at
+ <a href="site:deployment">Deployment Guide</a>. Details
about how OJB loads
+ the <em>OJB.properties</em> file can be found in
+ <a href="site:ojb-properties">OJB-properties guide</a>.
Details about how OJB loads
+ the mapping files can be found in
+ <a href="site:repository/load-repository">repository
guide</a>.
+ </p>
</answer>
- </faq>
+ </faq>
- <faq id="noDefaultConnection">
+ <faq id="loadProperties">
<question>
- Error message: <em>... no 'default-connection' attribute
enabled in the jdbc connection descriptor...</em>.
+ Error message: <em>Could not load properties
file'OJB.properties'...</em>?
</question>
<answer>
<p>
- Set attribute <a
href="site:repository/default-connection"><em>default-connection</em></a> in
- <a
href="site:repository/jdbc-connection-descriptor">jdbc-connection-descriptor</a>
before using
- the <em>shortcut</em>-method to lookup
<code>PersistenceBroker</code> instances.
+ Please have a look in <a href="#loadConfiguration">section
above</a>.
</p>
</answer>
- </faq>
+ </faq>
+
+ <faq id="couldNotBorrowConnection">
+ <question>
+ Error message: <em>Could not borrow connection from pool...</em>
+ </question>
+ <answer>
+ <p>
+ The used connection pool is exhausted, because
+ </p>
+ <ul>
+ <li>
+ the connection pool size is too low or the database
+ maximum connection limit is reached. Check your connection
pool size
+ setting within the
+ <a href="site:repository/connection-pool">connection pool
element</a> in repository file.
+ </li>
+ <li>
+ of Jdbc-Driver issues (wrong arguments, classpath issues,
missing driver jar, ...).
+ </li>
+ <li>
+ the specified <em>validation query</em> (in
+ <a
href="site:repository/jdbc-connection-descriptor">jdbc-connection-descriptor</a>)
+ cause an error.
+ </li>
+ <li>
+ too many concurrent threads exhaust the connection pool.
+ </li>
+ <li>
+ of a <em>PersistenceBroker</em> leak (How to automatically
+ <a href="site:pb-guide/detect-leak">detect broker
leaks</a>).
+ </li>
+ </ul>
+ </answer>
+ </faq>
+
+ <faq id="couldNotBorrowBroker">
+ <question>
+ Error message: <em>Borrow broker from pool failed,...</em>.
+ </question>
+ <answer>
+ <p>
+ The <a
href="ext:persistence-broker"><code>PersistenceBroker</code></a> instance
+ pool is exhausted because
+ </p>
+ <ul>
+ <li>
+ the broker pool size is too low. Check entry
<em>maxActive</em> in
+ <a href="ext:ojb.properties">OJB.properties</a> file.
+ </li>
+ <li>
+ too many concurrent threads exhaust the connection pool
used by the broker instances
+ (this would cause a nested connection pool error, see
+ <a href="#couldNotBorrowConnection">connection pool error
message</a>).
+ </li>
+ <li>
+ of a <code>PersistenceBroker</code> <em>leak</em>. The
mandatory
+ <code>PersistenceBroker.close()</code> call (after use) is
missed. How to automatically
+ detect leaks can be found in the <a
href="site:pb-guide/detect-leak">persistence broker guide</a>.
+ </li>
+ </ul>
+ </answer>
+ </faq>
+
+ <faq id="noDefaultConnection">
+ <question>
+ Error message: <em>... no 'default-connection' attribute enabled
in the jdbc connection descriptor...</em>.
+ </question>
+ <answer>
+ <p>
+ Set attribute <a
href="site:repository/default-connection"><em>default-connection</em></a> in
+ <a
href="site:repository/jdbc-connection-descriptor">jdbc-connection-descriptor</a>
before using
+ the <em>shortcut</em>-method to lookup
<code>PersistenceBroker</code> instances.
+ </p>
+ </answer>
+ </faq>
- </faqsection>
</faqsection>
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