High Availability for Internet Information Server Using Doble-Take 4.x High Availability for Internet Information Server Using Doble-Take 4.x pblished April 2000 NSI and Doble-Take are registered trademarks of Network Specialists Inc. All other prodcts are trademarks of their respective companies. 1996 2000 NSI Software
Table of Contents Introdction... 1 Reqirements... 1 Naming Conventions... 2 Application Note Otline... 2 Protecting Yor IIS Data... 4 Install Software on the Sorce...4 Install and Configre Software on the Target... 5 Configre and Begin Mirroring and Replication... 7 Configre Failover and Begin Failre Monitoring... 10 Monitoring Failover... 14 When the Sorce is Online... 14 When the Sorce Fails and Failover is Initiated... 16 When the Sorce Fails and Failover is Completed... 16 Restoring Yor IIS Data... 17 NSI Software Contact Information... 22
Introdction Internet Information Server (IIS) 4.0 is a standards-based Web and File Transfer Protocol (FTP) server from Microsoft. IIS is designed to operate on the Windows 2000/NT network operating system and is an Internet standards-compliant HTTP (Hypertext Transfer Protocol) server that also incldes FTP and several other valable Web and FTP related services. IIS permits the ser to flly design, create, deploy, and manage Web sites of any size. This docment describes the steps necessary to configre Doble-Take version 4.x to provide high availability for Windows 2000/NT servers rnning IIS. These procedres allow a secondary server to assme the identity and role of a failed IIS server while maintaining the availability of IIS services with minimal disrption or data loss. To complete these instrctions, install IIS and Doble-Take, and configre Doble-Take for replication and failover. De to the complexities of these applications, this docment is intended for network administrators with experience installing, configring, and maintaining network applications inclding Doble-Take and IIS. Reqirements Two servers that meet one of the following operating system reqirements: Microsoft Windows NT 4.0 with Service Pack 4 or higher Microsoft Windows 2000 The two servers shold both be rnning the same operating system. Althogh cross-platform mirroring and replication are available, NSI Software recommends that the two servers be the same platform for effective failover and failback. It is recommended that both sorce and target servers be standalone servers. (Yo may experience problems with promotion and demotion dring failover if either of the machines are Primary or Backp Domain Controllers.) One copy of Microsoft Internet Information Server 4.0 Two licensed copies of Doble-Take 4.x The Doble-Take Chngname tility Both servers mst be connected to the same physical network The Chngname.exe tility is available on the NSI Software web site at www.nsisoftware.com/pdates/chngname.htm.
Naming Conventions Doble-Take for Windows 2000/NT provides failover capabilities for mltiple sorce (prodction) servers to be monitored by and failed over to a single target (high availability) server. When a sorce server fails, Doble-Take cases the target server to add (or optionally replace) the failed server s name and IP address. For most applications, this provides nearly instantaneos failover, with no need to reboot the target server, and it allows server-based applications already rnning on the target server to contine withot interrption. When Doble-Take performs failover by adding the failed servers name to the existing name of the target this is known as mlti-naming since the target machine is actally broadcasting mltiple names on the network and responding for mltiple IP address. Unlike most client-server applications, IIS is sensitive to the primary name of the server on which it is rnning. If it was installed on server SOURCE, and server TARGET adds the name SOURCE, IIS will not rn becase the server s primary name is still TARGET. However, with the Doble-Take Chngname tility, yo are provided the ability to temporarily change the primary name on the target to make failover of name sensitive services, sch as IIS, possible. Application Note Otline Protecting Yor IIS Data 1. Install Software on the Sorce a. Install IIS 4.0. b. Install Doble-Take 4.x. 2. Install and Configre Software on the Target a. Unplg the sorce machine from the network. This step allows the target machine to se the sorce s name for the IIS installation. b. Change the active server name of the target to the name of the sorce sing the Chngname.exe tility. c. Install IIS 4.0. d. Set IIS services to manal startp. e. Install Doble-Take 4.x. f. Change the active server name of the target back to its original identity by sing the Chngname.exe tility. g. Reconnect the sorce machine back to the network. High Availability for Internet Information Server Using Doble-Take 4.x Page 2 of 22
3. Configre and Begin Mirroring and Replication a. Identify the IIS data to protect and create the Doble-Take replication set. b. Connect the replication set to the target and begin mirroring and replication. 4. Configre Failover and Begin Failre Monitoring a. Create scripts to be sed dring the failover and failback processes. b. Configre the failover settings. c. Begin failre monitoring. Monitoring Failover 1. When the Sorce is Online 2. When ths Sorce Fails and Failover is Initiated 3. When the Sorce Fails and Failover is Completed Restoring yor IIS Data 1. Rebild the sorce machine, if necessary. 2. Stop the IIS services on the target. 3. Initiate failback. 4. Bring the sorce online. 5. Restore the newer data from the target to the sorce. 6. Start the IIS services on the sorce. High Availability for Internet Information Server Using Doble-Take 4.x Page 3 of 22
Protecting Yor IIS Data Install Software on the Sorce 1. Install IIS 4.0 on the sorce, if it is not already installed. 2. Record the drive and directory where yo installed IIS. For example, the defalt directories for IIS are <drive>:\inetpb\. IIS Installation Drive and Directory: 3. Install Doble-Take 4.x on the sorce machine sing the installation defalts. See the Doble-Take gide Getting Started for details. Depending on how yo are sing IIS, yo may or may not need to apply specific Doble-Take settings for applications that are transaction-based. If yo are sing IIS to maintain and display web data only, then IIS is not performing transaction-based operations. If yo are sing IIS to gather information via yor web site, then IIS is performing transaction-based operations. Dring the Doble-Take 4.x installation, select the appropriate selection transacational applications or non-transactional applications on the Doble-Take Optimizations screen depending on how yo are sing IIS. See the Doble-Take gide Getting Started for frther details. High Availability for Internet Information Server Using Doble-Take 4.x Page 4 of 22
Install and Configre Software on the Target 1. Remove the sorce machine from the network. This step will allow the target machine to se the sorce s identity for this section. 2. Change the active server name of the target to the name of the sorce sing the Chngname.exe tility. The Chngname.exe tility is available on the NSI Software web site at www.nsisoftware.com/pdates/chngname.htm. Select Start, Rn and enter the command: <drive>:\<directory>\chngname /s sorce_name For sorce_name, enter the name of yor sorce. 3. Now that the target s active server name is identical to the sorce s name, install IIS on the target sing the same drive and directory specifications recorded in step 2 of the previos section. WARNING: When prompted, do not reboot the target machine at this time. 4. In Control Panel, Services, set the IIS services to manal startp. This step allows the Doble-Take failover and failback scripts that yo will be creating later to control the starting and stopping of the IIS services. If yo are sing Windows 2000, the IIS services that yo will need to stop inclde: FTP Pblishing Service IIS Admin Service Network News Transport Protocol (NNTP) (this service may not be applicable to yor environment) Simple Mail Transport Protocol (SMTP) World Wide Web Pblishing Service If yo are sing Windows NT 4.0, the IIS services that yo will need to stop inclde: Content Index FTP Pblishing Service IIS Admin Service Microsoft NNTP Service (this service may not be applicable to yor environment) Microsoft SMTP Service World Wide Web Pblishing Service High Availability for Internet Information Server Using Doble-Take 4.x Page 5 of 22
5. Install Doble-Take 4.x on the target machine sing the installations defalts. See the Doble-Take gide Getting Started for details.. Depending on how yo are sing IIS, yo may or may not need to apply specific Doble-Take settings for applications that are transaction-based. If yo are sing IIS to maintain and display web data only, then IIS is not performing transaction-based operations. If yo are sing IIS to gather information via yor web site, then IIS is performing transaction-based operations. Dring the Doble-Take 4.x installation, select the appropriate selection transacational applications or non-transactional applications on the Doble-Take Optimizations screen depending on how yo are sing IIS. See the Doble-Take gide Getting Started for frther details. WARNING: When prompted, do not reboot the target machine at this time. 6. In Control Panel, Services, doble-click the Doble-Take service. 7. Mark the check box Allow Service to Interact with Desktop and click OK. 8. Change the active server name of the target back to its original identity by sing the Chngname.exe tility. Select Start, Rn and enter the command: <drive>:\<directory>\chngname /t 9. Reconnect yor sorce machine back to the network. 10. Reboot the target machine. High Availability for Internet Information Server Using Doble-Take 4.x Page 6 of 22
Configre and Begin Mirroring and Replication 1. Select Start, Programs, Doble-Take, Management Console. 2. Doble-click the sorce machine to log on. 3. Right-click the sorce machine and select Properties. 4. Select the Startp tab. If yo are sing Doble-Take 3.0.x, the Startp tab will not contain the File Differeences and Fll options as pictred below. 5. By defalt, Perform Remirror After Ato-Reconnect will be selected. Disable this option so that the sorce does not remirror files after failback. If this option is selected, the sorce will remirror files and potentially overwrite newer files on the target machine. 6. Click OK to save the change. If yo are sing Doble-Take 3.1.x, contine with step 9. High Availability for Internet Information Server Using Doble-Take 4.x Page 7 of 22
7. If yo are sing Doble-Take 3.0.x, select the Memory tab. The Doble-Take 3.0.x, defalt Pagefile is 32768KB. If yo intend to mirror and replicate large amonts of data, increase the Doble-Take pagefile. Yo will want to increase it to at least 256MB (262,144,000KB). The maximm pagefile is 1GB. See the Doble-Take 3.0.x readme.txt for additional performance enhancements. 8. Click OK to close the Server Properties. If yo made any changes to the Doble-Take pagefile settings, yo will need to stop and restart the Doble-Take service to apply the change. 9. Right-click yor sorce machine and select New, Replication Set and enter the desired name for the replication set. 10. Select the IIS data yo want to protect. It is not necessary to replicate the application files since they already exist on the target machine, so yo will probably only inclde the IIS data directories. By defalt, this is <drive>:\inetpb\. If yo have any IIS data stored on other drives, be sre and select those directories as well. 11. Right-click the replication set name and select Save to save the replication set. High Availability for Internet Information Server Using Doble-Take 4.x Page 8 of 22
12. Drag and drop the replication set onto the target. The Connection Manager dialog box opens. 13. The Sorce Server, Target Server, Replication Set, and Rote fields will atomatically be poplated. If yo have mltiple IP addresses on yor Target, verify the Rote field is set to the correct network path. For detailed information on connecting a sorce and target, reference Doble-Take s User s Gide. 14. Select the One To One mapping so that the replication set data is transmitted to the same directory strctre on the target. 15. Click Connect to start the mirror and replication processes. High Availability for Internet Information Server Using Doble-Take 4.x Page 9 of 22
Configre Failover and Begin Failre Monitoring 1. If a failre occrs, yo will want to have the IIS services start on the target machine atomatically. To do this, create a batch file called postover.bat sing the sample batch file below. Save the batch file to the same directory where yor Doble-Take files are installed. POSTOVER.BAT rem This command temporarily changes the name of the server. Yo will need to rem replace <drive>:\<directory>\ with the location of yor Doble-Take script rem files and replace sorce_name with the name of the sorce machine. The rem Chngname tility shold be located in the same directory as the rem Doble-Take script files. <drive>\<directory>\chngname /s sorce_name rem The next two sections are configred by defalt to rn with IIS 4.0 on Windows rem 2000. Yo may need to comment the defalt lines ot and ncomment the set of lines rem for the Windows version yo are sing. rem If yo are sing IIS 4.0 and Windows 2000 se the following five commands. net start "FTP Pblishing Service" net start "Network News Transport Protocol" net start "Simple Mail Transport Protocol" net start "World Wide Web Pblishing Service" rem If yo are sing IIS 4.0 and Windows NT 4.0 se the following six commands. rem net start "IIS Admin Service" rem net start "Content Index" rem net start "FTP Pblishing Service" rem net start "Microsoft SMTP Service" rem net start "Microsoft NNTP Service" rem net start "World Wide Web Pblishing Service" rem This command changes the target name back to its original name. Yo will rem need to replace <drive>:\<directory>\ with the location of yor rem Doble-Take script files. The Chngname tility shold be located in the same rem directory as the Doble-Take script files. <drive>\<directory>\chngname /t High Availability for Internet Information Server Using Doble-Take 4.x Page 10 of 22
2. After a failre is resolved, yo will be ready to bring yor sorce back online. At this time, yo will want to stop the IIS services on the target atomatically. To do this, create a batch file called preback.bat sing the sample batch file below. Save the batch file to the same directory where yor Doble-Take files are installed. PREBACK.BAT rem This file is configred by defalt to rn with IIS 4.0 on Windows 2000. Yo may rem need to comment the defalt lines ot and ncomment the set of lines rem for the Windows version yo are sing. rem If yo are sing IIS 4.0 and Windows 2000 se the following command. net stop "IIS Admin Service" /y rem If yo are sing IIS 4.0 and Windows NT 4.0 se the following three commands. net stop "Content Index" net stop "FTP Pblishing Service" net stop "IIS Admin Service" /y These sample sample batch files are available on the NSI Software web site at www.nsisoftware.com/download/iisscrp.exe. 3. Select Start, Programs, Doble-Take, Failover Control Center. 4. Select the target machine from the list of available machines. If the target yo need is not displayed, click Add Target, enter the machine name, and click OK. Sorce Name: Larry_Legend IP Address: 200.100.20.81 Target Name: Perses IP Address: 200.100.20.82 Configration Before Failover High Availability for Internet Information Server Using Doble-Take 4.x Page 11 of 22
5. To add a monitor for the selected target, click Add Monitor. Type the name of the sorce machine or click Browse to select it, and click OK. The Monitor Settings window will open. 6. In the Monitor Settings window, select the IP address that is going to failover and verify that the Perform Failover By option Adding Sorce Identity to Target is selected. High Availability for Internet Information Server Using Doble-Take 4.x Page 12 of 22
7. Click Scripts and insert the scripts that were created in steps 1 and 2 on page 10 and page 11. 8. Click OK to go back to the Monitor Settings dialog box. 9. Click OK to begin monitoring the sorce machine. In the event of a sorce machine failre, yor target machine is now ready to stand in for yor sorce. Failed Sorce Target Name: Larry_Legend and Perses IP Address: 200.100.20.81 and 200.100.20.82 Configration After Failover High Availability for Internet Information Server Using Doble-Take 4.x Page 13 of 22
Monitoring Failover Now that replication and failover monitoring are configred and started, yo will need to know if and when there is a problem. Since it can be essential to qickly know the stats of yor machines, Doble-Take offers varios methods for monitoring the stats of failover. When the Failover Control Center is rnning, yo will see for visal indicators: The Failover Control Center Time to Fail contdown The Failover Control Center stats bar located at the bottom of the window The Failover Control Center colored bllets to the left of each IP address and sorce machine The Windows desktop icon tray containing a failover icon When the Sorce is Online Dring normal operation when the sorce machine is online and responding, the failover indicators identify that the monitored sorce is still commnicating with the target. Yo can minimize the Failover Control Center and, althogh it will not appear in yor Windows taskbar, it will still be active and the failover icon will still appear in the desktop icon tray. The Failover Control Center Time to Fail conter is conting down and resetting each time a heartbeat is received from the sorce machine. The Failover Control Center stats bar at the bottom of the window indicates that the target machine is monitoring. The Failover Control Center bllet before each monitored IP address and sorce machine name is green. The Windows desktop icon tray contains a failover icon depicting two compters. This icon indicates that both the sorce and target machines are online and active. High Availability for Internet Information Server Using Doble-Take 4.x Page 14 of 22
When the Time to Fail vale has decreased by 25% of the entire timeot period, the bllet changes from green to yellow, indicating that the target has not received a response from the sorce. The yellow bllet is a cation signal. If a response from the sorce is received, the contdown resets and the bllets change back to green. If the contown reaches zero withot the target receiving a response from the sorce, failover begins. High Availability for Internet Information Server Using Doble-Take 4.x Page 15 of 22
When the Sorce Fails and Failover is Initiated If the sorce machine experiences a failre, failover is initiated. The failover indicators identify that a monitored sorce is in the process of being failed over to its target. The Failover Control Center Time to Fail contdown vale is 0. The Failover Control Center stats bar at the bottom of the window displays the sorce machine and IP address crrently being assmed by the target. If the failover process completes qickly, this indicator may appear and disappear before yo have time to read it or actally see it. The Failover Control Center bllet before each failed IP address and machine name is yellow. The Windows desktop icon tray contains a failover icon depicting only one compter. This icon indicates that at least one monitored sorce is either in the process of being failed over or is in a failed over state. When the Sorce Fails and Failover is Completed When the failover process is complete, the visal indicators are again pdated. The Failover Control Center Time to Fail contdown is replaced with the Failed Over message. The Failover Control Center stats bar at the bottom of the window indicates that monitoring has contined. The Failover Control Center bllet before each failed IP address and machine name is red. The Windows desktop icon tray contains a failover icon depicting only one compter. This icon indicates that at least one monitored sorce is either in the process of being failed over or is in a failed over state. Once failover is complete, any clients accessing the IIS server will be atomatically directed to the target. For additional detailed information on failover and other monitoring tools, see Doble-Take s User s Gide. High Availability for Internet Information Server Using Doble-Take 4.x Page 16 of 22
Restoring Yor IIS Data If yor sorce experiences a failre, sch as a power, network, or disk failre, yor target machine will stand in for the sorce while yo resolve the sorce machine isses. Dring the sorce machine downtime, data is pdated on the target machine. When yor sorce machine is ready to come back online, the data is no longer crrent and mst be pdated with the new data on the target machine. 1. Make sre the sorce machine is offline and disconnected from the network. 1. Resolve the sorce machine problem that cased the failre. If yo mst rebild yor hard drive, contine with step 3. If yo do not need to rebild yor hard drive, contine with step 6 below. 2. Install Window 2000/NT and the appropriate service pack. Since yor sorce machine is not connected to the network, go ahead and se the sorce s original name and IP address. 3. Install Doble-Take 4.x sing the installation defalts.. Depending on how yo are sing IIS, yo may or may not need to apply specific Doble-Take settings for applications that are transaction-based. If yo are sing IIS to maintain and display web data only, then IIS is not performing transaction-based operations. If yo are sing IIS to gather information via yor web site, then IIS is performing transaction-based operations. Dring the Doble-Take 4.x installation, select the appropriate selection transacational applications or non-transactional applications on the Doble-Take Optimizations screen depending on how yo are sing IIS. See the Doble-Take gide Getting Started for frther details. 4. Install IIS sing the same drive and directory settings recorded in step 2 of Install Software on the Sorce on page 4. High Availability for Internet Information Server Using Doble-Take 4.x Page 17 of 22
5. In Control Panel, Services, set the IIS services to manal startp. If yo are sing Windows 2000, the IIS services that yo will need to stop inclde: FTP Pblishing Service IIS Admin Service Network News Transport Protocol (NNTP) (this service may not be applicable to yor environment) Simple Mail Transport Protocol (SMTP) World Wide Web Pblishing Service If yo are sing Windows NT 4.0, the IIS services that yo will need to stop inclde: Content Index FTP Pblishing Service IIS Admin Service Microsoft NNTP Service (this service may not be applicable to yor environment) Microsoft SMTP Service World Wide Web Pblishing Service 6. Verify that IIS is not rnning on the sorce. The IIS services mst not be rnning at this time. Depending on the type of failre, yor services may be set to manal startp, bt cold still be rnning. Stop yor IIS services and set them to manal startp. 7. On the target machine, select Start, Programs, Doble-Take, Failover Control Center. 8. Select the target machine that is crrently standing in for the failed sorce. High Availability for Internet Information Server Using Doble-Take 4.x Page 18 of 22
9. Select the failed sorce and click Failback. The pre-failback script entered dring the failover configration stops the IIS services on the target so that no additional changes can be made. 10. Yo will be prompted to determine if yo want to contine monitoring the sorce server. Do not choose Contine or Stop at this time. 11. Connect the sorce machine to the network. 12. Open the Doble-Take Management Console (Start, Programs, Doble-Take, Management Console), highlight the sorce machine, and ensre that the IIS replication set is not connected so that replication does not contine after failback is complete. If the replication set is connected, disconnect it by right-clicking it and selecting Disconnect. 13. After the sorce is back online, select whether yo want to contine monitoring the sorce machine. High Availability for Internet Information Server Using Doble-Take 4.x Page 19 of 22
14. To begin the restoration process, open the Doble-Take Management Console and select Tools, Restoration Manager. Yo can also rn the Doble-Take DTCL atomated restoration script, which can be fond in Doble-Take s User s Gide, to complete the remaining steps in this section. 15. Complete the appropriate fields as described below. Original Sorce The name of the sorce machine where the data original resided. Restore From The name of the target machine that contains the replicated data. Replication Set The name of the replication set to be restored. Restore To The name of the machine where yo the data will be restored. This may or may not be the same as the original sorce machine. 16. Identify the correct drive mappings for the data and any other restoration options necessary. For detailed information on the restoration options, see Doble-Take s User s Gide. High Availability for Internet Information Server Using Doble-Take 4.x Page 20 of 22
17. Verify that the selections yo have made are correct and click Restore. The restoration procedre time will vary depending on the amont of data that yo have to restore. 18. After the restoration is complete, start the IIS services on the sorce machine. 19. Reestablish the Doble-Take IIS replication set connection. At this time, yor data is restored back to yor sorce machine, the sorce machine is again the primary IIS server, and, if yo selected to contine failover monitoring, the target is available to stand in for the sorce in the event of a failre. High Availability for Internet Information Server Using Doble-Take 4.x Page 21 of 22
NSI Software Contact Information Web Site Company and prodct information, inclding a list of recent press releases, is available on or web site at www.nsisoftware.com. Crrent pdates of all prodcts can be fond at www.nsisoftware.com/pdates. Technical Spport When contacting s for technical spport, please inclde the following identifying information, in addition to the description of yor problem or sitation yor name, yor company name, and a phone nmber where yo can be reached; yor NSI prodct name, version nmber, and its serial nmber and activation code; and a brief description of yor operating system and network configration in which the NSI prodct is operating. Web Site Spport An online spport form is available at www.nsisoftware.com/pages/spportform.htm. E-mail Spport Or e-mail address is spport@nsisoftware.com. Phone Spport Technical spport hors are Monday throgh Friday, 8:00 a.m. - 6:00 p.m. (EST). Cstomers within the U.S., please call (800) 775-8674. Cstomers otside of the U.S., please call +1 317 598-2066. Twenty-for-hor emergency spport is also available to all NSI cstomers. Unless yor service agreement covers 24-hor spport, there is a charge for each instance. After a message has been left, a technician will be paged and will retrn yor call. Sales and Corporate Office For information abot NSI Software or or prodcts, please contact: (800) 775-4674, if calling from within the U.S. +1 201 656-2121, if calling from otside the U.S. Bsiness hors are Monday throgh Friday, 9:00 a.m. - 5:00 p.m. (ET). Please address all other correspondence as follows: NSI Software 80 River Street, Site 5B Hoboken, NJ 07030 Direct fax correspondence to (201) 656-2727. Docmentation For comments or sggestions abot NSI Software docmentation, e-mail the docmentation manager at docmentation@nsisoftware.com. High Availability for Internet Information Server Using Doble-Take 4.x Page 22 of 22