Reply-To: dev@qpid.apache.org Delivered-To: mailing list commits@qpid.apache.org Received: (qmail 6219 invoked by uid 99); 4 Mar 2018 21:22:55 -0000 Received: from git1-us-west.apache.org (HELO git1-us-west.apache.org) (140.211.11.23) by apache.org (qpsmtpd/0.29) with ESMTP; Sun, 04 Mar 2018 21:22:55 +0000 Received: by git1-us-west.apache.org (ASF Mail Server at git1-us-west.apache.org, from userid 33) id 2C8E9F4EAB; Sun, 4 Mar 2018 21:22:53 +0000 (UTC) Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: orudyy@apache.org To: commits@qpid.apache.org Date: Sun, 04 Mar 2018 21:23:19 -0000 Message-Id: <68deb492260240a4a8fb720d880be06f@git.apache.org> In-Reply-To: <024522893f2c4345a9396fbccda7f609@git.apache.org> References: <024522893f2c4345a9396fbccda7f609@git.apache.org> X-Mailer: ASF-Git Admin Mailer Subject: [27/32] qpid-site git commit: QPID-8112: Update site content for Qpid Broker-J 7.0.2 http://git-wip-us.apache.org/repos/asf/qpid-site/blob/91891e66/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-Getting-Started.html ---------------------------------------------------------------------- diff --git a/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-Getting-Started.html b/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-Getting-Started.html new file mode 100644 index 0000000..0fe9d22 --- /dev/null +++ b/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-Getting-Started.html @@ -0,0 +1,151 @@ + + + + + Chapter 3. Getting Started - Apache Qpid™ + + + + + + + + + + + + + +

+ + +

+ + + + + +

+ + +

Chapter 3. Getting Started
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Chapter 3. Getting Started

Table of Contents

3.1. Introduction
3.2. Starting/Stopping the broker on Windows
3.3. Starting/Stopping the broker on Unix
3.4. Log file
3.5. Using the command line

3.1. Introduction

+ This section describes how to start and stop the Broker, and outlines the various command line options. +

+ For additional details about the broker configuration store and related command line arguments see + Chapter 5, Initial Configuration. + The broker is fully configurable via its Web Management Console, for details of this see + Section 6.2, “Web Management Console”. +

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+ +

+ + + +

+ Apache Qpid, Messaging built on AMQP; Copyright © 2015 + The Apache Software Foundation; Licensed under + the Apache + License, Version 2.0; Apache Qpid, Qpid, Qpid Proton, + Proton, Apache, the Apache feather logo, and the Apache Qpid + project logo are trademarks of The Apache Software + Foundation; All other marks mentioned may be trademarks or + registered trademarks of their respective owners +

+ + http://git-wip-us.apache.org/repos/asf/qpid-site/blob/91891e66/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-Backup.html ---------------------------------------------------------------------- diff --git a/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-Backup.html b/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-Backup.html new file mode 100644 index 0000000..fc7fbf9 --- /dev/null +++ b/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-Backup.html @@ -0,0 +1,145 @@ + + + + + 10.10. Backups - Apache Qpid™ + + + + + + + + + + + + + +

+ + +

+ + + + + +

+ + +

10.10. Backups
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10.10. Backups

It is recommend to use the hot backup script to periodically backup every node in the + group. Section 11.2.2, “BDB-HA”.

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10.9. Security	Home	10.11. Reset Group Information

+ +

+ + + +

+ + http://git-wip-us.apache.org/repos/asf/qpid-site/blob/91891e66/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-Behaviour.html ---------------------------------------------------------------------- diff --git a/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-Behaviour.html b/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-Behaviour.html new file mode 100644 index 0000000..e1e1b77 --- /dev/null +++ b/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-Behaviour.html @@ -0,0 +1,226 @@ + + + + + 10.4. Behaviour of the Group - Apache Qpid™ + + + + + + + + + + + + + +

+ + +

+ + + + + +

+ + +

10.4. Behaviour of the Group
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10.4. Behaviour of the Group

This section first describes the behaviour of the group in its default configuration. It + then goes on to talk about the various controls that are available to override it. It + describes the controls available that affect the durability of transactions and + the data consistency between the master and replicas and thus make trade offs between + performance and reliability.

10.4.1. Default Behaviour

Let's first look at the behaviour of a group in default configuration.

In the default configuration, for any messaging work to be done, there must be at least + quorum nodes present. This means for example, in a three node group, + this means there must be at least two nodes available.

When a messaging client sends a transaction, it can be assured that, before the control + returns back to his application after the commit call that the following is true:

At the master, the transaction is written to disk and OS level caches + are flushed meaning the data is on the storage device.
At least quorum minus 1 replicas, acknowledge the receipt of + transaction. The replicas will write the data to the storage device + sometime later.

If there were to be a master failure immediately after the transaction was committed, + the transaction would be held by at least quorum minus one replicas. For example, if we had + a group of three, then we would be assured that at least one replica held the + transaction.

In the event of a master failure, if quorum nodes remain, those nodes hold an election. + The nodes will elect master the node with the most recent transaction. If two or more nodes + have the most recent transaction the group makes an arbitrary choice. If quorum number of + nodes does not remain, the nodes cannot elect a new master and will wait until nodes rejoin. + You will see later that manual controls are available allow service to be restored from + fewer than quorum nodes and to influence which node gets elected in the event of a + tie.

Whenever a group has fewer than quorum nodes present, the virtualhost will be + unavailable and messaging connections will be refused. If quorum disappears at the very + moment a messaging client sends a transaction that transaction will fail.

You will have noticed the difference in the synchronization policies applied the master + and the replicas. The replicas send the acknowledgement back before the data is written to + disk. The master synchronously writes the transaction to storage. This is an example of a + trade off between durability and performance. We will see more about how to control this + trade off later.

10.4.2. Synchronization Policy

The synchronization policy dictates what a node must do when it + receives a transaction before it acknowledges that transaction to the rest of the + group.

The following options are available:

SYNC. The node must write the transaction to disk and flush + any OS level buffers before sending the acknowledgement. SYNC is offers the highest + durability but offers the least performance.
WRITE_NO_SYNC. The node must write the transaction to disk + before sending the acknowledgement. OS level buffers will be flush as some point + later. This typically provides an assurance against failure of the application but not + the operating system or hardware.
NO_SYNC. The node immediately sends the acknowledgement. The + transaction will be written and OS level buffers flushed as some point later. NO_SYNC + offers the highest performance but the lowest durability level. This synchronization + policy is sometimes known as commit to the network.

It is possible to assign a one policy to the master and a different policy to the + replicas. These are configured as attributes on the + virtualhost. By default the master uses SYNC and replicas use + NO_SYNC.

10.4.3. Node Priority

Node priority can be used to influence the behaviour of the election algorithm. It is + useful in the case were you want to favour some nodes over others. For instance, if you wish + to favour nodes located in a particular data centre over those in a remote site.

The following options are available:

Highest. Nodes with this priority will be more favoured. In + the event of two or more nodes having the most recent transaction, the node with this + priority will be elected master. If two or more nodes have this priority the algorithm + will make an arbitrary choice.
High. Nodes with this priority will be favoured but not as + much so as those with Highest.
Normal. This is default election priority.
Never. The node will never be elected even if the + node has the most recent transaction. The node will still keep up to date + with the replication stream and will still vote itself, but can just never be + elected.

Node priority is configured as an attribute on the + virtualhost node and can be changed at runtime and is effective immediately.

Important

Use of the Never priority can lead to transaction loss. For example, consider a group + of three where replica-2 is marked as Never. If a transaction were to arrive and it be + acknowledged only by Master and Replica-2, the transaction would succeed. Replica 1 is + running behind for some reason (perhaps a full-GC). If a Master failure were to occur at + that moment, the replicas would elect Replica-1 even though Replica-2 had the most recent + transaction.

Transaction loss is reported by message HA-1014.

10.4.4. Required Minimum Number Of Nodes

This controls the required minimum number of nodes to complete a transaction and to + elect a new master. By default, the required number of nodes is set to + Default (which signifies quorum).

It is possible to reduce the required minimum number of nodes. The rationale for doing + this is normally to temporarily restore service from fewer than quorum nodes following an + extraordinary failure.

For example, consider a group of three. If one node were to fail, as quorum still + remained, the system would continue work without any intervention. If the failing node were + the master, a new master would be elected.

What if a further node were to fail? Quorum no longer remains, and the remaining node + would just wait. It cannot elect itself master. What if we wanted to restore service from + just this one node?

In this case, Required Number of Nodes can be reduced to 1 on the remain node, allowing + the node to elect itself and service to be restored from the singleton. Required minimum + number of nodes is configured as an attribute on the + virtualhost node and can be changed at runtime and is effective immediately.

Important

The attribute must be used cautiously. Careless use will lead to lost transactions and + can lead to a split-brain in the event of a network partition. If used to temporarily restore + service from fewer than quorum nodes, it is imperative to revert it + to the Default value as the failed nodes are restored.

Transaction loss is reported by message HA-1014.

10.4.5. Allow to Operate Solo

This attribute only applies to groups containing exactly two nodes.

In a group of two, if a node were to fail then in default configuration work will cease + as quorum no longer exists. A single node cannot elect itself master.

The allow to operate solo flag allows a node in a two node group to elect itself master and + to operate sole. It is configured as an attribute on the + virtualhost node and can be changed at runtime and is effective immediately.

For example, consider a group of two where the master fails. Service will be interrupted + as the remaining node cannot elect itself master. To allow it to become master, apply the + allow to operate solo flag to it. It will elect itself master and work can continue, albeit + from one node.

Important

It is imperative not to allow the allow to operate solo flag to be set on both nodes at once. To + do so will mean, in the event of a network partition, a split-brain will + occur.

Transaction loss is reported by message HA-1014.

10.4.6. Maximum message size

+ Internally, BDB JE HA restricts the maximum size of replication stream records passed from the master + to the replica(s). This helps prevent DOS attacks. + If expected application maximum message size is greater than 5MB, the BDB JE setting + je.rep.maxMessageSize and Qpid context variable qpid.max_message_size + needs to be adjusted to reflect this in order to avoid running into the BDB HA JE limit. +

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10.3. Creating a group	Home	10.5. Node Operations

+ +

+ + + +

+ + http://git-wip-us.apache.org/repos/asf/qpid-site/blob/91891e66/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-ClientFailover.html ---------------------------------------------------------------------- diff --git a/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-ClientFailover.html b/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-ClientFailover.html new file mode 100644 index 0000000..687597c --- /dev/null +++ b/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-ClientFailover.html @@ -0,0 +1,148 @@ + + + + + 10.6. Client failover - Apache Qpid™ + + + + + + + + + + + + + +

+ + +

+ + + + + +

+ + +

10.6. Client failover
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10.6. Client failover

As mentioned above, the clients need to be able to find the location of the active + virtualhost within the group.

Clients can do this using a static technique, for example , utilising the failover feature of the Apache Qpid + JMS and Apache Qpid JMS AMQP 0-x clients where the client has a list of all the nodes, and tries each node in + sequence until it discovers the node with the active virtualhost.

Another possibility is a dynamic technique utilising a proxy or Virtual IP (VIP). These + require other software and/or hardware and are outside the scope of this document.

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10.5. Node Operations	Home	10.7. Disk space requirements

+ +

+ + + +

+ + http://git-wip-us.apache.org/repos/asf/qpid-site/blob/91891e66/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-CreatingGroup.html ---------------------------------------------------------------------- diff --git a/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-CreatingGroup.html b/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-CreatingGroup.html new file mode 100644 index 0000000..1897fe0 --- /dev/null +++ b/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-CreatingGroup.html @@ -0,0 +1,182 @@ + + + + + 10.3. Creating a group - Apache Qpid™ + + + + + + + + + + + + + +

+ + +

+ + + + + +

+ + +

10.3. Creating a group
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10.3. Creating a group

This section describes how to create a group. At a high level, creating a group involves + first creating the first node standalone, then creating subsequent nodes referencing the first + node so the nodes can introduce themselves and gradually the group is built up.

A group is created through either Web Management or the REST API. These instructions + presume you are using Web Management. To illustrate the example it builds the group + illustrated in figure Figure 10.1, “3-node group deployed across three Brokers.”

Install a Broker on each machine that will be used to host the group. As messaging + clients will need to be able to connect to and authentication to all Brokers, it usually + makes sense to choose a common authentication mechanism e.g. Simple LDAP Authentication, + External with SSL client authentication or Kerberos.
Select one Broker instance to host the first node instance. This choice is an + arbitrary one. The node is special only whilst creating group. Once creation is + complete, all nodes will be considered equal.
Click the Add button on the Virtualhost Panel on the Broker + tab.
+
1. Give the Virtualhost node a unique name e.g. weather1. The + name must be unique within the group and unique to that Broker. It is best if the + node names are chosen from a different nomenclature than the machine names + themselves.
2. Choose BDB_HA and select New group +
3. Give the group a name e.g. weather. The group name must be + unique and will be the name also given to the virtualhost, so this is the name the + messaging clients will use in their connection url.
4. Give the address of this node. This is an address on this node's host that + will be used for replication purposes. The hostname must be + resolvable by all the other nodes in the group. This is separate from the address + used by messaging clients to connect to the Broker. It is usually best to choose a + symbolic name, rather than an IP address.
5. Now add the node addresses of all the other nodes that will form the group. In + our example we are building a three node group so we give the node addresses of + chaac:5000 and indra:5000.
6. Click Add to create the node. The virtualhost node will be created with the + virtualhost. As there is only one node at this stage, the role will be + master.
+
Figure 10.2. Creating 1st node in a group

+
Now move to the second Broker to be the group. Click the Add + button on the Virtualhost Panel on the Broker tab of the second Broker.
+
1. Give the Virtualhost node a unique name e.g. + weather2.
2. Choose BDB_HA and choose Existing group +
3. Give the details of the existing node. Following our + example, specify weather, weather1 and + thor:5000
4. Give the address of this node.
5. Click Add to create the node. The node will use the existing details to + contact it and introduce itself into the group. At this stage, the group will have + two nodes, with the second node in the replica role.
6. Repeat these steps until you have added all the nodes to the group.
+
Figure 10.3. Adding subsequent nodes to the group

+

The group is now formed and is ready for us. Looking at the virtualhost node of any of the + nodes shows a complete view of the whole group.

Figure 10.4. View of group from one node

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10.2. High Availability Overview	Home	10.4. Behaviour of the Group

+ +

+ + + +

+ + http://git-wip-us.apache.org/repos/asf/qpid-site/blob/91891e66/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-DiskSpace.html ---------------------------------------------------------------------- diff --git a/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-DiskSpace.html b/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-DiskSpace.html new file mode 100644 index 0000000..ea7f28b --- /dev/null +++ b/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-DiskSpace.html @@ -0,0 +1,147 @@ + + + + + 10.7. Disk space requirements - Apache Qpid™ + + + + + + + + + + + + + +

+ + +

+ + + + + +

+ + +

10.7. Disk space requirements
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10.7. Disk space requirements

In the case where node in a group are down, the master must keep the data they are missing + for them to allow them to return to the replica role quickly.

By default, the master will retain up to 1hour of missed transactions. In a busy + production system, the disk space occupied could be considerable.

This setting is controlled by virtualhost context variable + je.rep.repStreamTimeout.

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10.6. Client failover	Home	10.8. Network Requirements

+ +

+ + + +

+ + http://git-wip-us.apache.org/repos/asf/qpid-site/blob/91891e66/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-Network-Requirements.html ---------------------------------------------------------------------- diff --git a/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-Network-Requirements.html b/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-Network-Requirements.html new file mode 100644 index 0000000..f1e2b31 --- /dev/null +++ b/content/releases/qpid-broker-j-7.0.2/book/Java-Broker-High-Availability-Network-Requirements.html @@ -0,0 +1,148 @@ + + + + + 10.8. Network Requirements - Apache Qpid™ + + + + + + + + + + + + + +

+ + +

+ + + + + +

+ + +

10.8. Network Requirements
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10.8. Network Requirements

The HA Cluster performance depends on the network bandwidth, its use by existing traffic, + and quality of service.

In order to achieve the best performance it is recommended to use a separate network + infrastructure for the Qpid HA Nodes which might include installation of dedicated network + hardware on Broker hosts, assigning a higher priority to replication ports, installing a group + in a separate network not impacted by any other traffic.

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+ +

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Project

Messaging APIs

Servers and tools

Resources

Chapter 3. Getting Started

3.1. Introduction

Project

Messaging APIs

Servers and tools

Resources

10.10. Backups

Project

Messaging APIs

Servers and tools

Resources

10.4. Behaviour of the Group

10.4.1. Default Behaviour

10.4.2. Synchronization Policy

10.4.3. Node Priority

Important

10.4.4. Required Minimum Number Of Nodes

Important

10.4.5. Allow to Operate Solo

Important

10.4.6. Maximum message size

Project

Messaging APIs

Servers and tools

Resources

10.6. Client failover

Project

Messaging APIs

Servers and tools

Resources

10.3. Creating a group

Project

Messaging APIs

Servers and tools

Resources

10.7. Disk space requirements

Project

Messaging APIs

Servers and tools

Resources

10.8. Network Requirements