HA fo Azure (VM Depot) High Availability (HA) for Azure (VM Depot) Feature Description

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1 High Availability (HA) for Azure (VM Depot) Feature Description VERSION: 3.0 UPDATED: SEPTEMBER 2015

2 Copyright Notices Copyright KEMP Technologies, Inc.. All rights reserved.. KEMP Technologies and the KEMP Technologies logo are registered trademarks of KEMP Technologies, Inc.. KEMP Technologies, Inc. reserves all ownership rights for the LoadMaster product line including software and documentation. The use of the LoadMaster Exchange appliance is subject to the license agreement. Information in this guide may be modified at any time without prior notice. Microsoft Windows is a registered trademarks of Microsoft Corporation in the United States and other countries. All other trademarks and service marks are the property of their respective owners. Limitations: This document and all of its contents are provided as is. KEMP Technologies has made efforts to ensure that the information presented herein are correct, but makes no warranty, express or implied, about the accuracy of this information. If any material errors or inaccuracies should occur in this document, KEMP Technologies will, if feasible, furnish appropriate correctional notices which Users will accept as the sole and exclusive remedy at law or in equity. Users of the information in this document acknowledge that KEMP Technologies cannot be held liable for any loss, injury or damage of any kind, present or prospective, including without limitation any direct, special, incidental or consequential damages (including without limitation lost profits and loss of damage to goodwill) whether suffered by recipient or third party or from any action or inaction whether or not negligent, in the compiling or in delivering or communicating or publishing this document. Any Internet Protocol (IP) addresses, phone numbers or other data that may resemble actual contact information used in this document are not intended to be actual addresses, phone numbers or contact information. Any examples, command display output, network topology diagrams, and other figures included in this document are shown for illustrative purposes only. Any use of actual addressing or contact information in illustrative content is unintentional and coincidental. Portions of this software are; copyright (c) Frank Denis. All rights reserved; copyright (c) 2002 Michael Shalayeff. All rights reserved; copyright (c) 2003 Ryan McBride. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY THE ABOVE COPYRIGHT HOLDERS ''AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. The views and conclusions contained in the software and documentation are those of the authors and should not be interpreted as representing official policies, either expressed or implied, of the above copyright holders. Portions of the LoadMaster software are copyright (C) 1989, 1991 Free Software Foundation, Inc. 51 Franklin Street, Fifth Floor, Boston, MA , USA and KEMP Technologies Inc. is in full compliance of the GNU license requirements, Version 2, June Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. Copyright KEMP Technologies, Inc. All Rights Reserved. 2

3 Portions of this software are Copyright (C) 1988, Regents of the University of California. All rights reserved. Redistribution and use in source and binary forms are permitted provided that the above copyright notice and this paragraph are duplicated in all such forms and that any documentation, advertising materials, and other materials related to such distribution and use acknowledge that the software was developed by the University of California, Berkeley. The name of the University may not be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Portions of this software are Copyright (C) 1998, Massachusetts Institute of Technology Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. Portions of this software are Copyright (C) , Jean loup Gailly and Mark Adler This software is provided 'as is', without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software. Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions: 1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required. 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. 3. This notice may not be removed or altered from any source distribution. Portions of this software are Copyright (C) 2003, Internet Systems Consortium Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies. THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. Used, under license, U.S. Patent Nos. 6,473,802, 6,374,300, 8,392,563, 8,103,770, 7,831,712, 7,606,912, 7,346,695, 7,287,084 and 6,970,933 Copyright KEMP Technologies, Inc. All Rights Reserved. 3

4 Table of Contents 1 Introduction HA in LoadMaster for Azure Prerequisites Configure the LoadMasters Troubleshooting Virtual Machine Inaccessible Query the Health Check Port Run a TCP Dump Sync Problems References Document History Copyright KEMP Technologies, Inc. All Rights Reserved. 4

5 Introduction 1 Introduction When deploying an application using the Windows Azure Infrastructure as a Solution (IaaS) offering, chances are you need to provide load balancing and other application delivery functions such as content switching, SSL Termination and IPS. When using KEMP s LoadMaster for Azure, you can not only address your needs of application delivery but also of High Availability (HA). Deploying a single LoadMaster for Azure does not provide you with the high availability you need for your applications. When deploying a pair of LoadMasters in Azure, you can achieve high availability for your application using details provided in this document. Copyright KEMP Technologies, Inc. All Rights Reserved. 5

6 HA in LoadMaster for Azure 2 HA in LoadMaster for Azure Some important notes regarding how HA operates in the LoadMaster for Azure, are listed below: If you are familiar with HA on a regular (non Azure) LoadMaster, please take note that Azure uses a slightly different mechanism. Synchronization of Virtual Service settings only occurs from the master to the slave. Changes made to the master will be replicated to the slave. However, changes made to the slave are never replicated to the master. The replication (synchronization) of Virtual Service settings (from master to slave) is not instant in all cases and may take a few moments to complete If the master unit fails, connections will be directed to the slave unit. The master unit is the master and will never become the slave, even if it fails. Similarly, the slave unit will never become the master. When the master unit comes back up, connections will automatically be directed to the master again. Virtual Service configuration changes should never be made to the slave unit because these changes will not be replicated to the master. All Virtual Service Configuration changes should be made in the master unit. If the master unit is down, no Virtual Service configuration changes should be made. The HA Check Port must be set to the same port on both the master and slave units for HA to work correctly Copyright KEMP Technologies, Inc. All Rights Reserved. 6

7 Prerequisites 3 Prerequisites The following prerequisites must be met before proceeding to a high availability configuration: Application VMs deployed in Azure in a Virtual Network Application VMs may be configured to use single Cloud Service with no application endpoints created Application endpoints will be created on Cloud Services for LoadMaster VMs Application VM management endpoints can be created if VPN is not used Two LoadMaster VMs deployed in Azure on same Virtual Network as Application VMs Both LoadMaster devices licensed and configured Each published as part of the same cloud service Both LoadMasters should be configured to be part of an availability set The following diagram provides overview of configuration described above: Figure 3 1: Example architecture To configure high availability using the LoadMaster, the following configuration must be in place: Application VMs are installed and configured LoadMaster for Azure VMs are installed and configured Virtual Services for applications are created on both LoadMaster VMs Service Endpoints are created on Cloud Services for LoadMaster VMs Copyright KEMP Technologies, Inc. All Rights Reserved. 7

8 Prerequisites Following Management Endpoints are created on Cloud Services for LoadMaster VMs TCP Port 22 for SSH access TCP Port 8443 for Management Web User Interface (WUI) access UDP Port 53 for inbound DNS queries to GEO LoadMaster Copyright KEMP Technologies, Inc. All Rights Reserved. 8

9 4 The steps in this document reflect the steps in VM Depot. For steps in the Azure Marketplace ( refer to the HA for Azure (Marketplace), Feature Description. The steps and screenshots in this section were correct at the time of writing. However, the Azure interface changes regularly so please refer to Azure documentation for up-to-date steps if needed. Follow the steps below to set up the Virtual Machines in the Azure web portal: Figure 4 4 1: Networks 1. Select NETWORKS in the menu on the left. Copyright KEMP Technologies, Inc. All Rights Reserved. 9

10 Figure 4 2: Custom Create 2. Click NEW. 3. Select the network services option (circle icon) on the left. 4. Select VIRTUAL NETWORK. 5. Select CUSTOM CREATE. Copyright KEMP Technologies, Inc. All Rights Reserved. 10

11 Figure 4 3: Name and Location 6. Enter a NAME. 7. Select a LOCATION. 8. Click next (right arrow). Copyright KEMP Technologies, Inc. All Rights Reserved. 11

12 Figure 4 4: Skip this step 9. Skip the DNS Servers and VPN Connectivity step by clicking next (right arrow). Copyright KEMP Technologies, Inc. All Rights Reserved. 12

13 Figure 4 5: Add an Address Space 10. Add an address space. Copyright KEMP Technologies, Inc. All Rights Reserved. 13

14 Figure 4 6: Network creation 11. Wait for the network to be completely created. Copyright KEMP Technologies, Inc. All Rights Reserved. 14

15 Figure 4 7: Virtual Machines 12. Select Virtual Machines in the menu on the left. Copyright KEMP Technologies, Inc. All Rights Reserved. 15

16 Figure 4 8: From Gallery 13. Click NEW. 14. Select the compute option on the left (the first icon). 15. Select VIRTUAL MACHINE. 16. Select FROM GALLERY. Copyright KEMP Technologies, Inc. All Rights Reserved. 16

17 Figure 4 9: Select the image 17. Select MY IMAGES on the left. 18. Select the relevant Virtual LoadMaster (VLM) image. Before you can select the VLM image, it must be imported from VM Depot. For steps on how to do this, refer to the Feature Description, LoadMaster for Azure. Copyright KEMP Technologies, Inc. All Rights Reserved. 17

18 19. Enter a VIRTUAL MACHINE NAME. 20. Provide a password for the user. Figure 4 10: Virtual machine configuration This password will not be used. 21. Leave the SIZE and TIER set to the default values. Copyright KEMP Technologies, Inc. All Rights Reserved. 18

19 Figure 4 11: Virtual machine configuration step Select Create a new cloud service from the CLOUD SERVICE drop down menu. 23. Select your network. 24. Select Create an availability set. 25. Enter a name for the availability set. 26. Add endpoints for management. The external and internal ports are set to different values. As the cluster only has one name/ip address, different ports must be used to access the units individually. 27. Click next (the right arrow). Copyright KEMP Technologies, Inc. All Rights Reserved. 19

20 Figure 4 12: Uncheck VM AGENT 28. Remove the tick from the VM AGENT check box. Figure 4 13: VIRTUAL MACHINES Copyright KEMP Technologies, Inc. All Rights Reserved. 20

21 29. Select VIRTUAL MACHINES from the menu on the left. 30. Wait for the machine to provision. This may take some time. Figure 4 14: Cloud Services 31. Select CLOUD SERVICES in the menu on the left. 32. Confirm that the cloud service has also been deployed. Copyright KEMP Technologies, Inc. All Rights Reserved. 21

22 Figure 4 15: Create the second Virtual Machine 33. Create the second Virtual Machine, using a different name. Copyright KEMP Technologies, Inc. All Rights Reserved. 22

23 Figure 4 16: Cloud Service 34. Use the same cloud service as the one created for HA Select the AVAILABILITY SET that was created earlier. 36. Click the right arrow to continue. 37. Wait for the Virtual Machine to provision. This may take some time. Copyright KEMP Technologies, Inc. All Rights Reserved. 23

24 Figure 4 17: Endpoints 38. Select the Virtual Machines option on the left (monitor icon). 39. Select the HA1 machine. 40. Select ENDPOINTS. 41. Click ADD. Copyright KEMP Technologies, Inc. All Rights Reserved. 24

25 Figure 4 18: Add an endpoint 42. Add an endpoint. Copyright KEMP Technologies, Inc. All Rights Reserved. 25

26 Figure 4 19: Ports 43. Set the ports. Copyright KEMP Technologies, Inc. All Rights Reserved. 26

27 44. Configure the load balanced set. 45. Click the complete button (tick icon). Figure 4 20: Load balanced set Figure 4 21: Endpoints Copyright KEMP Technologies, Inc. All Rights Reserved. 27

28 46. Wait for the end point to be added. 47. Select the HA2 Virtual Machine on the left. 48. Click ADD. Figure 4 22: Add existing endpoint 49. Select the ADD AN ENDPOINT TO AN EXISTING LOAD BALANCED SET option. Click next (the right icon). Copyright KEMP Technologies, Inc. All Rights Reserved. 28

29 Figure 4 23: Endpoint details 50. Set the ports. 51. Wait for the endpoint to be added. 52. The probe now needs to be changed to an actual HTTP request in order for it to work. This can be done by running a command in Azure PowerShell. In order to connect to Azure with PowerShell, you need to download and install the Azure PowerShell. This is a separate application from the stock PowerShell. It can be downloaded here: us/documentation/articles/install configure powershell/ 53. Then, download the Add AzureAccount commandlet from us/library/dn aspx 54. When the commandlet has been downloaded, run it. An example command on how to do this is below: Set AzureLoadBalancedEndPoint ServiceName vlm azure ha LBSetName WWW ProbeProtocolHTTP ProbePath / ProbePort 8444 ProbeIntervalInSeconds 5 Once this is done you can set up the LoadMaster. License and set up as usual. For more information and steps on how to license, refer to the Feature Description, Licensing document. After licensing, follow the steps below to configure HA on the LoadMasters. Copyright KEMP Technologies, Inc. All Rights Reserved. 29

30 Configure the LoadMasters 5 Configure the LoadMasters There is only one IP address per Azure instance so the IP address of the interface will be the same as the IP address of any Virtual Services. If the machine is shut down from the Azure portal the IP address will be released. To configure LoadMaster for HA, follow the steps outlined in the sections below: 1. Access the WUI of the LoadMaster which will be the master unit. 2. In the main menu, select System Configuration > Miscellaneous Options > Azure HA Parameters. Figure 5 1: Master Unit 3. Select Master HA Mode in the Azure HA Mode drop down list. 4. Enter the Partner Name/IP address of the slave LoadMaster unit and click Set Partner Name/IP. 5. Enter the Health Check Port and click Set Check Port. The Health Check Port must be set to the same port on both the master and slave units for HA to function correctly. 6. Then, access the WUI of the slave unit. Complete steps 2 to 4 above in the slave unit, but select Slave HA Mode as the Azure HA Mode instead. HA will not work if both units have the same value selected for the Azure HA Mode. When HA is enabled on both devices, changes made to the Virtual Services in the master unit will be replicated to the slave. Figure 5 2: Master unit You can tell, at a glance, which unit is the master, and which is the slave, by checking the mode in the top bar of the LoadMaster. The current status of each LoadMaster, when HA is enabled, is shown as follows: Figure 3: Master unit Active Copyright KEMP Technologies, Inc. All Rights Reserved. 30

31 Configure the LoadMasters Figure 4: Slave unit Active Figure 5: Slave unit Stand By Copyright KEMP Technologies, Inc. All Rights Reserved. 31

32 Troubleshooting 6 Troubleshooting The sections below provide some basic troubleshooting tips. If further assistance is required, please contact KEMP Support: Virtual Machine Inaccessible It takes approximately five minutes for the Virtual Machine to become accessible after booting. 6.2 Query the Health Check Port In order to determine which LoadMaster to use as the master, Azure performs a HTTP health check of the partners. When experiencing issues with HA for Azure, it can be useful to query the HA health check port. This will provide information that can help to determine the status of the HA cluster. Copyright KEMP Technologies, Inc. All Rights Reserved. 32

33 Troubleshooting Figure 6 1: Health check port end point To query the HA health check port, create an end point in Azure for the health check port. Do this for each LoadMaster that needs to be checked. Figure 6 2: Status Then, access the end point via a browser to check the status. Copyright KEMP Technologies, Inc. All Rights Reserved. 33

34 Troubleshooting When querying or accessing this port on the LoadMasters if the master is up, the master will report 200 OK, Master is UP and the slave will report 503 Master is Up. If the master is down the slave will report 200 OK, Slave is UP (Master is DOWN). 6.3 Run a TCP Dump Running a TCP dump and checking the results can also assist with troubleshooting. To do this, follow the steps below in the LoadMaster WUI: 1. In the main menu, go to System Configuration > Logging Options > System Log Files. Figure 6 3: System Log Files 2. Click Debug Options. 3. In the TCP dump section, enter the relevant IP Address and the Azure HA Port. 4. Click Start. 5. Let the capture run for a few minutes. 6. Click Stop. 7. Click Download. 8. Analyse the results in a packet trace analyser tool such as Wireshark. Checks from the partner LoadMaster should appear in the results. If nothing is shown there is a problem, for example Azure may be blocking the connection. Copyright KEMP Technologies, Inc. All Rights Reserved. 34

35 Troubleshooting 6.4 Sync Problems In most scenarios the configuration settings are automatically synchronized between partners every two minutes. If a new Virtual Service is created, the settings are immediately synchronized. Because of this, creating a new Virtual Service is a good way of checking if the synchronization is working. To trace this, follow the steps below: 9. Start a TCP dump, as detailed in Section 6.3, but use port Create a Virtual Service. 11. Stop the TCP dump. 12. Download the TCP dump file. 13. Analyse the results. After creating a Virtual Service, a lot of traffic should have been immediately triggered. Generally, if a lot of packets are being transferred it means that the synchronization is working. If only a few packets are transferred, it may mean that the connection was unsuccessful. In this case, there may be a problem such as unmatched SSH keys. Copyright KEMP Technologies, Inc. All Rights Reserved. 35

36 References References Unless otherwise specified, the following documents can be found at documentation. Feature Description, Licensing Feature Description, LoadMaster for Azure Configuration Guide, WUI Feature Description, GEO Product Overview, GEO HA for Azure (Marketplace), Feature Description Azure Virtual Machines tutorials and guides: us/documentation/services/virtual machines/ Copyright KEMP Technologies, Inc. All Rights Reserved. 36

37 Document History Document History Date Change Reason for Change Version Resp. Feb 2014 Initial draft First draft of document 1.0 BS Mar 2014 Minor change Update to Copyright Notices 1.1 LB July 2014 Release updates Updates for a release 1.2 LB July 2014 Release updates Updates for b release 1.3 LB Feb 2015 Minor change Added reference 1.3 LB Mar 2015 Enhancements made Various improvements made 1.4 LB Sep 2015 Screenshots updated WUI Reskin 3.0 KG Copyright KEMP Technologies, Inc. All Rights Reserved. 37