Highly Available BizTalk

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Highly Available BizTalk

• Concepts Around the Implementation of BizTalk
  Server 2006 in a High Availability Environment
• Daniel Toomey Patrick Hood
• presenters

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Goal of This Presentation

• Not highly technical (i.e. no code)
• Not demo-heavy
• Discussion of the main concepts and strategy of
  HA in an integration solution
• Understand Microsoft recommended practices

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Definition of High Availability (HA)

• is a system design protocol and associated
  implementation that ensures a certain absolute
  degree of operational continuity during a given
  measurement period.
• (www.wikipedia.org/wiki/High_Availability)

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Definition of High Availability (HA)

• Redundancy of each functional component
• Seeks to eliminate single point of failure
• Single component failure triggers recovery
  mechanisms that are transparent to users of the
  system

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High Availability vs High Performance

• High Availability is about Failover
• Does not necessarily involve load balancing
• Active/Passive configuration
• Scaling Out
• High Performance is about Performance!!
• Typically about load balancing and managing high
  throughput
• Active/Active configuration
• Scaling Out or Scaling Up
• Not necessarily Highly Available

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High Availability and Integration
?
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High Availability in BizTalk

• BizTalk Components
• Databases (SQL Server)
• Services (Host Instances)
• Adapters (Send / Receive)
• Enterprise Single Sign-On (SSO)
• Process for ensuring High Availability is
  different for each of these components

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BizTalk Groups

• Out-of-the-box functionality for BizTalk allows
  for the easy (and default) establishment of
  BizTalk Groups
• A BizTalk Group is a collection of servers that
  host BizTalk services (hosts) which operate upon
  the same Message Box(es)
• All hosts within a BizTalk Server Group are based
  upon the same set of configuration and message
  storage databases
• Automatic Load Balancing

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HA for BizTalk Databases

• SQL Server supports BizTalk through data
  persistence
• Stores all configuration, business rules, message
  state and tracking info
• Stores the messages themselves
• Separates data from hosts that process the data
• The most critical component in a BizTalk
  architecture
• Can be implemented as a SQL Server Cluster
  (active / passive mode)

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HA for BizTalk Databases
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HA for BizTalk Databases

• Create global domain accounts
• Configure the SQL Server cluster before BizTalk
  installation
• Install BizTalk
• Run the BizTalk Configuration Wizard in custom
  configuration mode
• Specify the SQL Server cluster for the BizTalk
  databases

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HA for BizTalk Databases

• Failover Behaviour in BizTalk
• BizTalk databases are temporarily unavailable
  during failover
• In-process host instances are recycled until
  connection to the SQL Server is automatically
  restored
• Isolated host instances are paused, an error is
  generated in the BizTalk Server 2006 Application
  log and receive locations are disabled
• Once connection to the SQL databases is restored,
  document processing resumes normally and receive
  locations are enabled

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HA for BizTalk Databases

• SQL Server Database Mirroring
• Not currently a supported solution for ensuring
  high availability of the Microsoft BizTalk
  Server 2006 databases
• Potential problems maintaining transactional
  consistency in the BizTalk databases
• Log Shipping is the recommended practice for
  Disaster Recovery

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HA for BizTalk Hosts

• Hosts provide logical containers for
  functionality
• Receiving
• Sending
• Processing
• Recommended practice is to create hosts for each
  separate functionality
• Creates security boundaries
• Easier management scalability

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HA for BizTalk Hosts

• In-process Hosts
• Run inside of BizTalk runtime process
• Contain all non-Web-based artefacts
• Orchestrations
• Adapter send handlers
• Adaptor receive handlers (except for HTTP
  SOAP)
• Isolated Hosts
• Do not run inside of BizTalk runtime process
• HTTP and SOAP receive handlers

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HA for BizTalk Hosts

• BizTalk Server 2006 lets you separate hosts and
  run multiple host instances to provide high
  availability
• No additional clustering or load-balancing
  mechanism required because BizTalk Server 2006
  automatically distributes workload across
  multiple computers through host instances
• However, hosts running the receive handler for
  the following adapters require a load-balancing
  mechanism such as Network Load Balancing (NLB) to
  provide high availability
• HTTP
• SOAP
• BizTalk Message Queuing (MSMQT)

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HA for BizTalk Hosts (Receiving)

• Scaled Out Receiving Hosts

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HA for BizTalk Hosts (Receiving)

• Scaled Out Receiving Hosts (multiple clients)

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HA for BizTalk Hosts (Receiving)

• Using host instances on multiple computers
• FILE Adapter (point host instances to same UNC
  path)
• SQL Adapter (point host instances to same
  database table)
• Using host instances on multiple computers with
  NLB
• HTTP Adapter (subscribe to a shared clustered
  URL)
• Web Services Adapter (NLB distributes incoming
  messages)
• SharePoint Adapter (subscribe to a shared URL)
• MSMQT Adapter (NLB distributes incoming messages)
• Using a clustered BizTalk host (req. Enterprise
  Edition)
• FTP Adapter
• POP3 Adapter (multiple concurrent connections)
• MSMQ Adapter

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HA for BizTalk Hosts (Receiving)
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HA for BizTalk Hosts (Processing)

• Scaled Out Processing Hosts

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HA for BizTalk Hosts (Processing)

• Scaled Out Processing Hosts
• Orchestration state is maintained centrally in
  SQL Server, not locally on each BizTalk Server
  computer
• BizTalk load balances automatically
• One instance can complete a process started by
  another instance
• Proof of Concept

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BizTalk Host Load Balancing

• Used CallOrchestration sample from SDK
• Inserted Delay shapes and trace messages to log
  the step and the processing server
• Deployed to two servers in a BizTalk Group
• Submitted 1000 files
• Analysed the resulting logs
• For more than 25 of the files, processing steps
  were divided across more than one individual
  server (i.e. host instance)

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HA for BizTalk Hosts (Sending)

• Scaled Out Sending Hosts

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HA for BizTalk Hosts (Sending)

• Scaling Out Sending Hosts
• Similar to Processing Hosts Host Data
  Independence
• Special Considerations
• FTP Send Adapter
• Run in a clustered BizTalk Host
• Supports only one host instance running at a time
• MSMQ Adapter
• Cluster the MSMQ Service
• Cluster the BizTalk Host in the same group
• Configure MSMQ Send Handler within clustered host

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BizTalk Host Clustering

• Only necessary for certain adapters
• Requires BizTalk 2006 Enterprise Edition
• Requires BizTalk Servers to be configured as a
  Windows Server Cluster first
• Considerations
• Non-clustered host should not be run on a Windows
  Server cluster where Enterprise SSO is clustered
• More info
• http//msdn2.microsoft.com/en-us/library/aa560059.
  aspx

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Network Load Balancing (NLB)

• As previously mentioned, the following adapters
  require a load-balancing mechanism such as
  Network Load Balancing (NLB) to provide high
  availability
• HTTP
• SOAP
• BizTalk Message Queuing (MSMQT)
• Can load-balance the BAM portal BAS website
• Provides High Availability at the Network level,
  rather than the Resource level

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Network Load Balancing (NLB)

• NLB farm of servers appears as one server to
  clients
• Distributes load between the servers in the farm
• Each server in the NLB farm is aware of each
  other and automatically handle server
  unavailability
• Each server is fully self-contained
• BizTalk grouping provides balancing on hydration
  of long-running processes

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Network Load Balancing (NLB)
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Network Load Balancing (NLB)

• Easier and more flexible management
• Rolling OS update software deployment
• Uninterrupted availability and fault tolerance
• Server failure hardware update/replacement
• Better scalability
• True horizontal scalability
• Up to 32 servers in an NLB farm
• Multiple farms via DNS round-robin

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Network Load Balancing (NLB)

• Option of Hardware-based or Software-based NLB
  solution
• Hardware-based solution consists of a specialised
  network appliance e.g.
• F5 Networks
• Radware
• Cisco
• Foundary
• Alteon

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Windows NLB

• Full software NLB implementation
• Supported on all versions of Windows 2003 Server
• Supported on Windows 2000 Advanced Server and
  Datacenter Server Editions
• Generally a 5-10 overhead per server
• MSCS and Windows Network Load Balancing (NLB) are
  NOT supported on the same set of nodes

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Windows NLB

• Consider NICs Unicast vs. Multicast

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Windows NLB

• Port-rules multiple-host or single-host
• Affinity - can be set to
• None
• Single-client (or sticky-IP)
• Class C
• Host Priorities
• For BizTalk NLB, recommend multiple host, no
  affinity, even priority

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Enterprise Single Sign-On (SSO)

• Critical part of the BizTalk infrastructure
• Helps to secure information for the receive
  locations
• Master Secret Server
• Stores the encryption key used to secure data in
  the credentials database
• Must configure the first computer where SSO is
  installed as the Master Secret Server

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Enterprise Single Sign-On (SSO)

• If Master Secret Server fails, currently running
  operations continue but cannot encrypt new
  credentials
• BizTalk Server dependency on Master Secret
  Server
• Following link suggests that BizTalk runtime
  will fail after a period of time if Master Secret
  Server fails (courtesy of Tim Goodsell)
  http//www.microsoft.com/technet/prodtechnol/biz
  talk/2006/library/bts06clustering/c5fe4626-ff82-45
  cd-a62f-848fdc61e6ff.mspx?mfrtrue

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High Availability for Ent SSO

• Master Secret Server CANNOT exist on an NLB
  cluster
• Master Secret Server can be moved from BizTalk
  NLB servers (often to SQL Server infrastructure)
• Master Secret Server can be clustered

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Summary

• In an multi-system environment, High Availability
  means securing not only the individual systems
  themselves but also the integration architecture
• BizTalk Server 2006 can be implemented to support
  High Availability using a variety of techniques
  and configurations for the various components
• OTB functionality via BizTalk Server Groups
• SQL Server Failover Cluster
• Windows NLB Cluster
• Clustered Hosts

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References

• BizTalk High Availability
• Planning for High Availabilityhttp//msdn2.micros
  oft.com/en-us/library/aa558765.aspx
• Planning Your Platform for Fault
  Tolerancehttp//msdn2.microsoft.com/en-us/library
  /aa560135.aspx
• Creating a Highly Available BizTalk Server
  Environmenthttp//msdn2.microsoft.com/en-us/libra
  ry/aa560847.aspx
• Sample BizTalk Server High-Availability
  Scenarioshttp//msdn2.microsoft.com/en-us/library
  /aa578057.aspx
• Providing High Availability for BizTalk Server
  Databaseshttp//msdn2.microsoft.com/en-us/library
  /aa559920.aspx
• High Availability for the BizTalk Base EDI
  Adapterhttp//msdn2.microsoft.com/en-us/library/a
  a561569.aspx
• High Availability and the Microsoft Operations
  Frameworkhttp//msdn2.microsoft.com/en-us/library
  /aa560207.aspx

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References

• Enterprise Single Sign-On
• High Availability for Enterprise Single
  Sign-Onhttp//msdn2.microsoft.com/en-us/library/a
  a560674.aspx
• Backup, Cluster, Move Restore Enterprise
  SSOhttp//msdn2.microsoft.com/en-us/library/aa559
  192.aspxhttp//msdn2.microsoft.com/en-us/library/
  aa560589.aspxhttp//msdn2.microsoft.com/en-us/lib
  rary/aa559364.aspxhttp//msdn2.microsoft.com/en-u
  s/library/aa561823.aspx
• Window Server Cluster
• Using Windows Server Cluster to Provide High
  Availability for BizTalk Hostshttp//msdn2.micros
  oft.com/en-us/library/aa560059.aspx
• Improving Fault Tolerance in BizTalk Server 2006
  by Using a Windows Server Cluster (includes
  BizTalk MSCS and clustering the SSO)
  http//www.microsoft.com/technet/prodtechnol/bizta
  lk/2006/library/bts06clustering/6e6fee7b-1317-4e70
  -ab21-a145f2aa8594.mspx?mfrtrue

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References

• Windows Server 2003 Network Load Balancing
• http//articles.techrepublic.com.com/5100-6345_11-
  5208171.html
• http//www.west-wind.com/presentations/loadbalanci
  ng/NetworkLoadBalancingWindows2003.asp
• http//technet2.microsoft.com/WindowsServer/en/lib
  rary/65319bac-2efe-4764-8752-d091447dddbe1033.mspx
  ?mfrtrue
• http//technet2.microsoft.com/WindowsServer/en/lib
  rary/884c727d-6083-4265-ac1d-b5e66b68281a1033.mspx
  ?mfrtrue
• NLB Multicast vs. Unicast
• http//searchwincomputing.techtarget.com/tip/0,289
  483,sid68_gci1230735,00.html
• http//searchwincomputing.techtarget.com/tip/0,289
  483,sid68_gci1229240,00.html

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Questions?