WM4_0HighAvailabilityGuideIssue1 by Advantec Distribution

Cambium High Availability for Wireless Manager Server on a Linux Platform Setup Guide System Release 3.0 and later

Accuracy

While reasonable efforts have been made to assure the accuracy of this document, Cambium Networks assumes no liability resulting from any inaccuracies or omissions in this document, or from use of the information obtained herein. Cambium reserves the right to make changes to any products described herein to improve reliability, function, or design, and reserves the right to revise this document and to make changes from time to time in content hereof with no obligation to notify any person of revisions or changes. Cambium does not assume any liability arising out of the application or use of any product, software, or circuit described herein; neither does it convey license under its patent rights or the rights of others. It is possible that this publication may contain references to, or information about Cambium products (machines and programs), programming, or services that are not announced in your country. Such references or information must not be construed to mean that Cambium intends to announce such Cambium products, programming, or services in your country. Copyrights

This document, Cambium products, and 3rd Party Software products described in this document may include or describe copyrighted Cambium and other 3rd Party supplied computer programs stored in semiconductor memories or other media. Laws in the United States and other countries preserve for Cambium, its licensors, and other 3rd Party supplied software certain exclusive rights for copyrighted material, including the exclusive right to copy, reproduce in any form, distribute and make derivative works of the copyrighted material. Accordingly, any copyrighted material of Cambium, its licensors, or the 3rd Party software supplied material contained in the Cambium products described in this document may not be copied, reproduced, reverse engineered, distributed, merged or modified in any manner without the express written permission of Cambium. Furthermore, the purchase of Cambium products shall not be deemed to grant either directly or by implication, estoppel, or otherwise, any license under the copyrights, patents or patent applications of Cambium or other 3rd Party supplied software, except for the normal non‐exclusive, royalty free license to use that arises by operation of law in the sale of a product. Restrictions

Software and documentation are copyrighted materials. Making unauthorized copies is prohibited by law. No part of the software or documentation may be reproduced, transmitted, transcribed, stored in a retrieval system, or translated into any language or computer language, in any form or by any means, without prior written permission of Cambium. License Agreements

The software described in this document is the property of Cambium and its licensors. It is furnished by express license agreement only and may be used only in accordance with the terms of such an agreement. See the end user licenses published (redundantly) in the user guide or the server administration guide for Release 4.0. © 2012 Cambium Networks, Inc. All Rights Reserved.

Table of Contents Accuracy...................................................................................................................................... 2 Copyrights ................................................................................................................................... 2 Restrictions ................................................................................................................................. 2 License Agreements.................................................................................................................... 2

About High Availability.................................................................................... 7 1.1

Prerequisites for High Availability .................................................................................. 7

1.2

Caveats for High Availability Operations ........................................................................ 7

Setting Up High Availability ............................................................................. 9 2.1

Setting Up the WM and Network File Servers................................................................ 9

2.2

Configuring the Related Services.................................................................................. 13

Starting and Stopping the WM Service .............................................................15

Disabling and Uninstalling High Availability.......................................................17

Resources for Support ..........................................................................................19 Network Updater Help.............................................................................................................. 19 Community Forum .................................................................................................................... 19 Technical Support ..................................................................................................................... 20

List of Figures Figure 1: License Manager remote, database replication ............................................................................ 9 Figure 2: License Manager on each server, database replication............................................................... 10 Figure 3: License Manager remote, database remote (no replication) ...................................................... 10 Figure 4: License Manager on each server, database remote (no replication) .......................................... 11

List of Procedures Procedure 1: To set up WM and Pacemaker servers.................................................................................... 9 Procedure 2: To start the WM service........................................................................................................ 15 Procedure 3: To check the status of High Availability ................................................................................ 15 Procedure 4: To stop the WM service ........................................................................................................ 15 Procedure 5: To disable High Availability ................................................................................................... 17 Procedure 6: To uninstall High Availability ................................................................................................. 17

High Availability for WM on Linux

Issue 4 March 2012

About High Availability High Availability is an optional Wireless Manager (WM) software feature that supports a designated backup WM server fully ready for service whenever it is needed. This provides 

management server redundancy



optional replication of the database



replication of other important files, regardless of whether you configure database replication



seamless management and trap handling through primary server outages.

Technical support for your migration is available through contact on the sources listed in the user guide section titled "Contacting Support Representatives."

1.1

Prerequisites for High Availability The High Availability feature requires all of the following:

1.2



dedicated installation packages from Motorola



two Linux devices for WM servers with −

one specified as primary, the other as secondary (backup)

−

a dedicated IP address assigned to each server, in the same subnet as the other

−

one operator‐configurable virtual IP address that links to both of these servers

−

connectivity to License Manager

−

multicasting kept enabled in each server and in the network (for example, in switches and routers)



one further additional device for a standalone MySQL Server where remote database is preferred over database replication



Pacemaker with CoroSync software installed on the separate network file server to −

broker communications and perform load balancing between the WM servers

−

monitor and manage their services



operator mapping of related services on each server device to reflect the high availability deployment (mapping is not automated by the scripts from the distribution)



operator mapping from each server to the remote network file server



uninstallation, when desired, through only the documented, supported sequence.

Caveats for High Availability Operations The following caveats apply to any High Availability deployment of WM: 

No other network software is enabled on either WM server device.



While both WM servers remain in communication, switchover (swap of roles for primary and backup server) is smooth. However, if the servers lose communication with each other, then each behaves like the primary server role.

Issue 4 March 2012

High Availability for WM on Linux



Database replication is according to the MySQL Server replication feature. Where replication is configured, the database in the designated primary server is always considered the master copy, and in the secondary server is always considered the slave copy.



If the secondary server is ever out of service for longer than seven days, then the replicated database that it maintains becomes corrupted.



Restarts of the primary and secondary server must occur within seven days of each other to prevent corruption of the database that the secondary server maintains. However, a script that the distribution provides ensures the proper sequence and synchronization of server restarts as long as both are in service. If an out‐of‐service condition prevents the script from ensuring this, then the operator must deliberately restart the primary server and then start the secondary server (after verifying that the primary is again successfully operating).



A switchover event drops client sessions that were up in the primary server. As in single‐ server deployments, a dropped client session spawns a message in the client, advising the user that the connection has been interrupted, that the interface should be closed, and that a new client session should be launched.



WM and MySQL services must be controlled by only the high availability feature and its scripts (without operator intervention).

High Availability for WM on Linux

Issue 4 March 2012

Setting Up High Availability important ........... Before performing the procedures that this chapter provides, carefully review both Prerequisites for High Availability on Page 7 and Caveats for High Availability Operations on Page 7.

2.1

Setting Up the WM and Network File Servers To set up the servers, perform the following steps.

Procedure 1: To set up WM and Pacemaker servers 1.

Decide whether you want License Manager installed on each High Availability server device or on a separate (third) server within network reach of them.

note ............. Any of the Figure 1 through Figure 4 configurations is supported for High Availability.

Figure 1: License Manager remote, database replication Client/Device

Related Servers

High Availability WM Virtual IP

License Manager R0KD DHCP

Primary Server WM

Backup Server

MySQL

DNS BAM RADIUS

Issue 4 March 2012

High Availability for WM on Linux

Figure 2: License Manager on each server, database replication Client/Device

Related Servers

High Availability WM Virtual IP

R0KD Primary Server WM

Backup Server

BAM

MySQL

RADIUS

License Manager

DHCP DNS

Decide whether you want database replication (Figure 1 or Figure 2 above) or a single database on a third server (Figure 3 or Figure 4 below).

Figure 3: License Manager remote, database remote (no replication) Client/Device

Related Servers

High Availability WM Virtual IP

License Manager R0KD DHCP DNS BAM RADIUS

MySQL

Primary Server WM

Backup Server WM

High Availability for WM on Linux

Issue 4 March 2012

Figure 4: License Manager on each server, database remote (no replication) Client/Device

Related Servers

High Availability WM Virtual IP

R0KD DHCP DNS BAM RADIUS

MySQL

Primary Server WM

Backup Server

License Manager

Install WM Release 4.0 and License Manager as follows: ◦

On each server that is not currently running WM Release 4.0, perform the installation according to the instructions that the WM Release 4.0 quick start guide provides.

◦

On each server that is currently running one of those releases, perform the upgrade according to the instructions that the WM Release 4.0 server administration guide provides.

◦

While performing these WM software installation processes, install −

License Manager in the configuration that you decided upon in Step 1 of this procedure.

−

MySQL Server in the configuration that you decided upon in Step 2 of this procedure.

Install your WM license and device licenses, referring to either the quick start guide or the server administration guide as your reference.

On one of the WM servers, perform the following steps: a.

Use the WM Administrator Tool to configure the server. (See the server administration guide.)

Use the Discovery Configurator as many times as needed until all of the elements in your network have been discovered. (See the Release 4.0 user guide.)

Ensure that this server can push configuration values, generate reports, receive traps, and in all other ways perform as the WM management server described in the user guide, without throwing unexpected errors to the logs.

Stop the server.

On the other WM server, perform Step 5 of this procedure.

In the /etc/hosts files on each server device, add an entry that points to the other server device by hostname.

From http://www.clusterlabs.org/rpm/epel‐5/i386/, download the following packages into the /usr/local/motorola/wm/server/ha/packages directory of each of the servers: ◦

cluster-glue-1.0.4-1.el5.i386.rpm

◦

cluster-glue-libs-1.0.4-1.el5.i386.rpm

Issue 4 March 2012

High Availability for WM on Linux

◦

corosync-1.2.1-1.el5.i386.rpm

◦

corosynclib-1.2.1-1.el5.i386.rpm

◦

heartbeat-3.0.3-1.el5.i386.rpm

◦

heartbeat-libs-3.0.3-1.el5.i386.rpm

◦

pacemaker-1.0.8-5.el5.i386.rpm

◦

pacemaker-libs-1.0.8-5.el5.i386.rpm

◦

resource-agents-1.0.3-1.el5.i386.rpm

From http://download.fedora.redhat.com/pub/epel/5/i386/, download the following packages into the /usr/local/motorola/wm/server/ha/packages directory of each of the servers: ◦

esmtp-0.6.0-3.el5.i386.rpm

◦

libesmtp-1.0.4-5.el5.i386.rpm

10. On one of the WM servers, perform the following steps: a.

If the DVD drive is not /media/RHEL_5.5 i386 DVD/, perform the following steps: 1) Change directory to /usr/local/motorola/wm/server/ha/packages. 2) Open the file yum-rh-dvd.conf for editing. 3) Beneath the line name= Server Base, edit the value between baseurl=file:// and Server so that it is consistent with the location of your DVD drive, except representing each space with %20.

note ............. View the default on this line as an example of the required syntax.

4) Save and close the file. b.

Insert your Red Hat media into the DVD drive.

Change directory to /usr/local/motorola/wm/server/ha.

Open the file pacemaker.conf for editing.

For VIRTUAL_IP, set the address to the Virtual IP address that will always correlate to whatever server is primary at the time.

For BINDING_IP, set the address to the IP address of the local WM server, except set the last octet of that IP address to 0.

For CLUSTER_NODE1 and CLUSTER_NODE2, set the names to the hostnames of the local WM servers.

For REPLICATE_MYSQL 

set the value to yes if your configuration is like Figure 1 or Figure 2 on Page 10.



set the value to no if your configuration is like Figure 3 or Figure 4 on Page 11.

Save and close the file.

Enter ./pacemaker_install.sh.

Only if in Step 10h you set REPLICATE_MYSQL to yes, perform the following two substeps: 1) Enter ./create_db_rep_user.sh. 2) At the prompt, type in the password associated with the user root.

Remove the Red Hat media from the DVD drive.

11. On the other WM server, perform Step 10 of this procedure.

High Availability for WM on Linux

Issue 4 March 2012

12. On only one of the WM servers, perform the following steps: a.

Insert the Red Hat media into the DVD drive.

Enter the following commands: 

# corosync-keygen

This command creates the authentication keys. 

# scp /etc/corosync/authkey root@hostname:/etc/corosync/authkey

(where hostname identifies the other WM server) This command transfers the authentication keys to the other server. c.

Remove the Red Hat media from the DVD drive.

13. On one of the servers, enter ./ha_enable.sh. 14. On the other server, enter ./ha_enable.sh. 15. Only as described under Starting and Stopping the WM Service on Page 15, start both of the WM servers. 16. As described under Starting and Stopping the WM Service on Page 15, check the status of High Availability. 17. After the status tool has reported that both servers are running, enter on only one server ./wm_ha_initialize.sh. note ............. The initialize tool has configured Pacemaker to control and monitor WM in the High Availability configuration.

18. Ensure that the status tool output now indicates that one server is primary and the other is backup.

2.2

Configuring the Related Services The related servers and their services (some of which are shown on Pages 9 and 11) require attention and some or all may require adjustment as described in this section. If you use DHCP server on both WM servers, identically configure DHCP on each of them, initially and whenever you make a change of this configuration in one them. Either 

map the virtual IP address to the MAC address of each server.



set each DHCP server to be responsible for only a unique subset of the range of assignable IP addresses.

If you use DNS server on both WM servers, identically configure DNS on each of them, initially and whenever you make a change of this configuration in one them. Either 

point to the Virtual IP address (which always correlates to current primary server) as the lone DNS server



the actual IP addresses of both WM servers as multiple DNS servers.

If you deploy a BAM server, use the WM Administrator Tool to identically configure BAM in each, initially and whenever you make a change of this configuration in one them. Point to the Virtual IP address of WM. If you deploy a RADIUS server, identically configure RADIUS server on each of them, initially and whenever you make a change of this configuration in one them. Point to the Virtual IP address of WM.

High Availability for WM on Linux

Issue 4 March 2012

Starting and Stopping the WM Service important ........... Do not use the server start, stop, or restart tools described in other WM documents. Those are for only single-server deployments.

The High Availability distribution included dedicated scripts for starting the WM service, checking the status of High Availability, and stopping the WM service.

Procedure 2: To start the WM service 1.

On the server that you want to initially be the primary server, perform the following steps: a.

Change the working directory to /usr/local/motorola/wm/server/ha (if not already in this directory).

Enter ./wm_ha_start.sh.

Enter crm_mon to open an instance of the Pacemaker console to the dynamic output of its monitoring tool.

Wait until the output of the tool has identified the running server as primary.

Press Ctrl+C to close the monitoring console.

On the other server, perform Step 1 of this procedure.

Use Procedure 3 to check the server roles and the status of the HA feature.

Procedure 3: To check the status of High Availability 7.

On either server (the second is suggested, since this procedure typically follows Procedure 2), either ◦

enter ./wm_ha_status.sh to launch the High Availability status tool, which generates HA status output once and then automatically exits.

◦

enter crm_mon to open an instance of the Pacemaker console to the dynamic output of its monitoring tool.

Review the output.

If you executed crm_mon in Step 2, press Ctrl+C to close the monitoring console.

note ............. In future status checks, you can add the -1 option to the crm_mon command to cause Pacemaker to perform a single check, report the static output of that check, and then automatically exit its console.

Procedure 4: To stop the WM service 10. On the secondary server, perform the following steps: a.

Change the working directory to /usr/local/motorola/wm/server/ha (if not already in this directory).

Enter ./wm_ha_stop.sh.

11. On the primary server, perform Step 1 of this procedure.

High Availability for WM on Linux

Issue 4 March 2012

Disabling and Uninstalling High Availability If you ever want to disable the High Availability feature, perform the following steps.

Procedure 5: To disable High Availability 1.

On the secondary server, perform the following steps: a.

Change the working directory to /usr/local/motorola/wm/server/ha (if not already in this directory).

Enter ./wm_ha_stop.sh.

On the primary server, perform Step 1 of this procedure.

While still in the working directory /usr/local/motorola/wm/server/ha of the secondary server, enter ./ha_disable.sh.

While still in the working directory /usr/local/motorola/wm/server/ha of the primary server, enter ./ha_disable.sh.

On the server that will be the single‐server WM instance, use the WM Administrator Tool to start WM, as described in the server administration guide. (Do not use the wm_ha_start.sh script.)

To remove the High Availability feature and all of the scripts and configuration files that have operated it, perform the following steps.

Procedure 6: To uninstall High Availability 1.

Change the working directory to /usr/local/motorola/wm/server/ha.

Enter ./pacemaker_uninstall.sh.

High Availability for WM on Linux

Issue 4 March 2012

Resources for Support Network Updater Help These release notes call attention to Release 4.0 changes in the Network Updater tool. The effects of these changes are fully described in the document Network Updater On‐Line Help for Release 4.0. The user should search that document for information before consulting other sources of information. From the Network Updater application main menu, select HelpContents to open that resource.

Community Forum The technical support Community Forum is part of the support web site and can be used for asking questions directly to the support team. Questions and answers are accessible to all so that any customer can benefit from the same dialogue. To access this forum, visit http://www.cambiumnetworks.com/forum/. The following is an example of the contents of the forum page:

Issue 4 March 2012

High Availability for WM on Linux

This forum requires authentication for posting.

Technical Support You can obtain support for Wireless Manager from any or all of the following sources:



Wireless Manager setup guide, administration guide, and release notes.



Cambium Networks support web page: http://www.cambiumnetworks.com/support. This page provides links to information on all products and tools, as well as access to customer support materials and interactive support forums. Some of these resources are restricted to registered users and channel partners.



the Community Forum. Visit http://www.cambiumnetworks.com/forum/. See Community Forum on Page 19.



direct contact with Cambium Networks Technical Support. This contact is available 7 days a week, 24 hours a day. To find the appropriate phone number based on your country or region, visit http://www.cambiumnetworks.com/support/technical.php.



a technical support case, which you can open at http://www.cambiumnetworks.com/support/support_case.php. The case captures basic information about answers you are seeking or the problem that your network is experiencing and provides this to the support team, who are available 7 days a week, 24 hours a day, and will respond. They will also provide a case number by which you and they can continue to track progress on issues that require deeper investigation.