(PDB-3947) Drop remaining activemq code, including upgrade shovel

Remove activemq entirely for version 6.  This means that (as allowed
by the versioning policy), it will not be possible to skip upgrading
to pdb 6 from pdb 4 without running pdb 5 without losing the content
of any existing queue.  See the documentation updates for further
information.

Author: rbrw

documentation/configure.markdown

@@ -662,48 +662,6 @@ aren't being processed quickly enough, then you could increasing this
 value in order to alleviate that, but this is unlikely to be the
 bottleneck for command processing.
 
-### `store-usage`
-
-**Note**: This setting is deprecated and is ignored by PuppetDB,
-except when migrating away from ActiveMQ.  It will be removed from
-PuppetDB in a future release.
-
-Sets the maximum amount of space in megabytes that
-PuppetDB's ActiveMQ can use for persistent message storage.
-
-### `temp-usage`
-
-**Note**: This setting is deprecated and ignored by PuppetDB, except
-when migrating away from ActiveMQ.  It will be removed from PuppetDB
-in a future release.
-
-Sets the maximum amount of space in megabytes that
-PuppetDB's ActiveMQ can use for temporary message storage.
-
-### `memory-usage`
-
-**Note**: This setting is deprecated and ignored by PuppetDB, except
-when migrating away from ActiveMQ.  It will be removed in a future
-release.
-
-This setting sets the maximum amount of memory in megabytes available for
-PuppetDB's ActiveMQ Broker.
-
-**Warning** Setting this value too high (such that memory-usage exceeds the size
-of the heap) can cause out of memory (OOM) errors. ActiveMQ does not treat this
-as a hard limit. In testing, we've seen it use up to `125%` of the specified
-value, and overall memory usage will also be affected by the `max-command-size`
-and `threads` parameters.
-
-### `max-frame-size`
-
-**Note**: This setting is deprecated and ignored by PuppetDB, except
-when migrating away from ActiveMQ.  It will be removed from PuppetDB
-in a future release.
-
-Sets the maximum frame size for persisted ActiveMQ messages
-supplied in bytes. Default value is 209715200 (or 200MB).
-
 ### `reject-large-commands`
 
 This is a Boolean that enables rejecting (returning an HTTP 413 error)

documentation/pdb_support_guide.markdown

@@ -42,11 +42,6 @@ message as a normal file inside `vardir`/stockpile/cmd/q, and while
 it's unlikely to be necessary, it's safe to manually remove queue
 commands when PDB is not running.
 
-Whenever PDB starts up it checks to see if it has already migrated
-older messages from ActiveMQ to stockpile by looking for the file
-`vardir`/mq-migrated.  If that file doesn't exist, then it migrates
-any older messages, and creates mq-migrated.
-
 The message names are designed to provide some information about their
 content.  For example:
 

documentation/puppetdb-faq.markdown

@@ -76,30 +76,6 @@ with ActiveRecord in Ruby. We have no plans to support any other databases,
 including MySQL, which lacks important features such as array columns and
 recursive queries.
 
-## Why does PDB crash on startup while upgrading?
-
-If you're upgrading from an older version of PDB that stored incoming
-commands in ActiveMQ, it's possible that you have a currupted KahaDB.
-If so, you might see an exception that mentions the KahaDB libraries
-(org.apache.activemq.store.kahadb). For example:
-
-    java.io.EOFException
-        at java.io.RandomAccessFile.readInt(RandomAccessFile.java:776)
-        at org.apache.activemq.store.kahadb.disk.journal.DataFileAccessor.readRecord(DataFileAccessor.java:81)
-
-This problem may be fixed by stopping PDB, moving the mq directory
-somewhere else, and restarting PDB, but any messages that were in the
-mq directory will be lost.
-
-Note that this ActiveMQ message:
-
-      2016-02-29 15:20:53,571 WARN  [o.a.a.b.BrokerService] Store limit is
-      102400 mb (current store usage is 1 mb). The data directory:
-      /home/wyatt/work/puppetdb-mq-tmp/mq/localhost/KahaDB only has 71730 mb of
-      usable space. - resetting to maximum available disk space: 71730 mb
-
-is harmless and does not indicate an issue.
-
 ## The PuppetDB daemon shuts down with a "Cannot assign requested address" error. What does this mean, and how do I fix it?
 
 ~~~

documentation/release_notes.markdown

@@ -15,6 +15,22 @@ canonical: "/puppetdb/latest/release_notes.html"
 [pqltutorial]: ./api/query/tutorial-pql.html
 [stockpile]: https://github.com/puppetlabs/stockpile
 [queue_support_guide]: ./pdb_support_guide.html#message-queue
+[upgrade_policy]: ./versioning_policy.html#upgrades
+
+## 6.0.0
+
+## Upgrading
+
+-  Support for ActiveMQ has been completely removed, meaning that
+   PuppetDB can no longer convert an existing queue to the new format
+   when upgrading from versions older than 4.3.0, but since PuppetDB's
+   [upgrade policy][upgrade_policy] forbids skipping major versions,
+   this should not present a problem since any version 5 release will
+   perform the conversion at startup.
+
+   As a result of the removal, these ActiveMQ specific configuration
+   options have been retired: `store-usage`, `temp-usage`,
+   `memory-usage`, and `max-frame-size`,
 
 ## 5.2.4
 

project.clj

@@ -168,13 +168,6 @@
                  [com.zaxxer/HikariCP]
                  [honeysql]
 
-                 ;; MQ connectivity
-                 [org.apache.activemq/activemq-broker "5.13.2"]
-                 [org.apache.activemq/activemq-kahadb-store "5.13.2"]
-                 [org.apache.activemq/activemq-pool "5.13.2"]
-                 ;; bridge to allow some spring/activemq stuff to log over slf4j
-                 [org.slf4j/jcl-over-slf4j "1.7.20"]
-
                  ;; WebAPI support libraries.
                  [bidi]
                  [clj-http "2.0.1"]

resources/ext/config/logback.xml

@@ -20,16 +20,9 @@
         </encoder>
     </appender>
 
-    <!-- Supress internal ActiveMQ logging -->
-    <logger name="org.apache.activemq" level="warn"/>
-
     <!-- Supress internal Spring Framework logging -->
     <logger name="org.springframework.jms.connection" level="warn"/>
 
-    <!-- Lower the log level for ActiveMQ KahaDB MessageDatabase -->
-    <logger name="org.apache.activemq.store.kahadb.MessageDatabase"
-        level="info"/>
-
     <appender name="STATUS" class="ch.qos.logback.core.rolling.RollingFileAppender">
         <file>/var/log/puppetlabs/puppetdb/puppetdb-status.log</file>
         <append>true</append>

resources/logback.xml

@@ -6,9 +6,6 @@
     </appender>
 
     <!-- Silence particularly noisy packages -->
-    <logger name="org.apache.activemq" level="warn"/>
-    <logger name="org.apache.activemq.store.kahadb.MessageDatabase"
-        level="info"/>
     <logger name="org.springframework.jms.connection" level="warn"/>
 
     <root level="info">