Lync Server 2010: High Availability [I3004]


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Lync Server 2010: High Availability [I3004]
WPC 2011

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Lync Server 2010: High Availability [I3004]

  1. 1. Lync Server 2010: Fabrizio VolpeHigh Availability [I3004] MVP Directory Services MCITP MCSE VMware VCP Fortinet FCNSP
  2. 2. Agenda Topologie di Riferimento _1 High Availability _2 Voice Resilience _3 Metropolitan Site Resiliency _4
  3. 3. Add : Cumulative Update 4 for Lync Server2010 Released
  4. 4. Topologia di Riferimento “Small Enterprise”Single Server Standard Edition Reference TopologyFor a smaller Enterprise• Deploy an Edge server and reverse proxy• Use PSTN or SIP trunks to provide telephony integration• Exchange UM for voice mail integration• Use Active Directory/DNS Services and internal PKI• Use Survivable Branch Appliances (SBAs) for resiliency in remote locations• Deploy Standard Edition in a “Paired” solution for failover and redundancy (primary registrar and a backup registrar)
  5. 5. Topologia di Riferimento “Small Enterprise”
  6. 6. Topologia di Riferimento “Large Enterprise”• Use DNS load balancing for SIP on Front End servers, Edge servers, and the Directory server• Use a Hardware Load Balancer (HLB) for Secure HTTP (HTTPS), Distributed Component Object Model (DCOM), Reverse Proxy, and Edge Pool for Remote Access, External Conferencing, and Federation• Deploy a Monitoring server to record call quality• Deploy an A/V Conferencing Pool for scalability, collocated on the Front End servers• Deploy a Director Pool, which is a dedicated server• Use PSTN or SIP Trunks to provide telephony integration• Deploy Exchange UM for voice-mail integration• Use AD/DNS Services and Internal public key infrastructure (PKI) for certificate management• Deploy SBAs for voice resiliency in each of the remote locations
  7. 7. Topologia di Riferimento “Large Enterprise”
  8. 8. Lync Server H.A. : Redundant Environment• Instant Messaging • Enterprise Edition: Multiple Front-End Server, Array of Edge Servers• Web Conferencing • Enterprise Edition: Multiple Front-End Servers, Array of Edge Servers• Voice • Multiple Mediation Servers and Gateways • Multiple voice routes• Monitoring Server • Clustered SQL database• Archiving Server • Clustered SQL database• Persistent Group Chat (Session Dialog Resiliency)
  9. 9. Add : External Users
  10. 10. Lync High Availability ArchitectureMicrosoft Lync Server 2010 User Services Database (Presence and Architecture: Conferencing) • Each registrar has its own SQL Express database • Registrar and User Services are collocated in the Registrar Database datacenter (but on different servers) (Registration and Routing) • All user end points register with same Front End • Users are load balanced by Registrars using a Distributed Hash Algorithm • Registrar can be installed in remote locations HLB (optional for SIP traffic) User 1 User 1
  11. 11. DNS Load Balancing DNS Load Balancing is NOT the same as DNS Round Robin •Lync clients and servers are able to understand multiple IP addresses DNS Server is •Clients failover if connectivity to one IP fails configured for •Servers failover as load balance traffic across these Ips Round Robin and returns a list of IP DNS Round addresses for a Pool Robin FQDN DNS Load complements balancing DNS Load Balancing•Pool.Test.Org resolves to IP1, IP2, IP3•DNS Server replies to 1st Query with (IP1, IP2, IP3)•DNS Server replies to 2nd Query with (IP2, IP1, IP3)•DNS Server replies to 3rd Query with (IP3, IP2, IP1)
  12. 12. DNS Load Balancing “In Azione”• A front-end servers register their fully qualified domain name (FQDN) as A records in DNS• When the Enterprise pool is created, the pool FQDN (that is, the SRV record) is registered to return from DNS the list of IP addresses of all the front-end servers • The client queries DNS to resolve the FQDN of the pool • query returns the list (172,24,32,151, 172,24,32,152, 172,24,32,153) to the client • The client chooses an IP address from the list at random and attempts to connect • If this connection fails, the client attempts to connect to the next IP address in the list
  13. 13. La Registrazione del Client• In Lync each front-end server in a pool has a completely independent registration database• Each user is assigned a predefined registration database (Registrar)• Multiple clients with same user, all clients must register to the same front-end server• The registrar assignment is calculated by a hash value of the user’s SIP URI• The client attempts to register with a random front-end, if it is not the primary registrar the front-end redirects the client to his registrar
  14. 14. Add : User Registrar Sequence
  15. 15. DNS Load Balancing Options DNS Load Balancing on Front End Pools and Director Pools • Supported only by servers running Lync Server 2010 and Lync Server 2010 clients DNS Load Balancing on Edge Server Pools DNS Load Balancing on Stand-Alone Mediation Server Pools• DNS load balancing does not replace the need for hardware load balancing for server pools• HTTP and HTTPS are session-state–oriented protocols• The configuration of load balancers is primarily for HTTP traffic
  16. 16. Add : Web Services FQDN Overrides
  17. 17. Hardware Load Balancing• Hardware load balancers that have been tested by the vendor and reviewed by Microsoft to meet Lync Server 2010 requirement
  18. 18. High Availability through VirtualizationServer Virtualization in Microsoft Lync Server 2010 virtual and physical servers within the same pool are not supportedIf you are implemented a highly available, virtualized, Lync Server deployment consider spreading similar workloads todifferent VM hostsLive Migration of Lync Server workloads have not been validated, and is not supported (Applicable to Hyper-V LiveMigration, and VMware Vmotion)Specifically, it has not been validated what the client experience would be if a live migration is performed on a LyncServer workload running an active conferenceDynamic memory has not been validated with Lync Server 2010 workloads, and specific guidance cannot be provided
  19. 19. SQL Server Failover Cluster per Lync• Microsoft Lync Server 2010 Central Management store holds user data for all Enterprise Edition servers• CMS cannot be installed on the same computer of other Lync roles• Microsoft Lync Server 2010 supports clustering for Microsoft SQL Server 2008, Microsoft SQL Server 2008 R2, and Microsoft SQL Server 2005 in an active/passive configuration• You should set up and configure the SQL Server cluster before you install and deploy the Enterprise Edition Front End Server and back- end database
  20. 20. Configurazione Lync su SQL Cluster Define the SQL Server store in Topology Builder by using the SQL Server instance virtual cluster name and the instance name of the SQL Server database Open Lync Server Start Topology Builder Management Shell The Select Database File In Topology Builder, as you Location page has two publish the topology, on options that determine how Install-CsDatabase the Create databases page, the database files will be click Advanced deployed to the SQL Server cluster
  21. 21. Lync su SQL Cluster : Short Video
  22. 22. Voice Resilience• Voice resiliency in Lync Server 2010 is achieved with a primary and backup registrar service• When Lync endpoints sign in, they are informed of both a primary and backup registrar pool associated with their account• The primary registrar pool will typically be the Front End pool where the user account is homed, except in branch office scenarios• Two different voice resilience scenarios : datacenter survivability and branch site survivability.
  23. 23. Datacenter Survivability• To provide the failover capability when the primary pool is unavailable, each Front End pool can be assigned a backup pool• This can be another pool in the same site, or more commonly will be a pool in a separate datacenter across a WAN link• When assigned, as clients sign in, they will receive information about which pool is the primary and which pool is the backup
  24. 24. Datacenter Survivability Architecture • There is no requirement for the primary and back- up pools to be of equal capacity or version • A Standard Edition pool can act as a back-up for an Enterprise Edition pool • SBA in the Branch Office can point to either Pool 1 or Pool 2 • Pool 1 and Pool 2 can act as a back-up registrar for each other
  25. 25. Registrar Failover• Backup pool maintains a monitor to check whether the primary pool is available at all times• This monitoring is accomplished through the use of heartbeat messages exchanged between the two pools• Only after the backup pool stops receiving heartbeat messages from the primary it begin accepting user registrations• The default timeout interval for the heart- beat messages is 300ms• Timeout can be modified by an administrator if a longer or shorter timeout period is require
  26. 26. Scenari di Failure • Failure of (or loss of connectivity to) Pool 1 • Failure of (or loss of connectivity to) Pool 2 • Failure of (or loss of connectivity to) SBA
  27. 27. Servizi Disponibili Durante un FailoverFeatures that are available in a failover scenario include • PSTN Calls—Outbound calls • Inbound call availability is dependent on the PSTN carrier • Internal Calls—Internal voice calls are possible between users in the same site and to additional sites • Call Control—Users are able to use basic call features such as hold and transfer • Advanced features such as call forwarding, simultaneous ringing, and team call • Instant Messaging—Instant messaging service is available, but only between two parties • No instant messaging conferencing services are available. • Audio/Video Calls—Audio and video calls are between two parties only. • Audio/video conferencing services are unavailable. • Call Detail Records
  28. 28. Servizi Non Disponibili Durante un FailoverFeatures that are unavailable to users in a failover scenario include • Conferencing Auto Attendant • Conferencing - Any type of conferencing involving more than two parties is unavailable • Instant message • Audio/video conferences • Presence-Based Routing • Call Park • Response Group Service—Any workflows and queues associated with the failed pool are unavailable • Agents will be unable to sign in • Call Forwarding Settings - Users are unable to update or change their call forwarding settings • Voicemail Delivery • Voicemail Retrieval
  29. 29. Branch-Site Survivability Host between 25 and Survivable Branch 1000 users at your Appliance branch site Survivable Branch Host between 1000 and Server or two 2000 Survivable Branch Appliances Deploy as a central site with a Up to 5000 Standard Edition server rather than as a branch site
  30. 30. Survivable Branch Appliance
  31. 31. Servizi Durante Branch ResiliencyFeatures Available Features UnavailablePSTN Inbound and Outbound calls Inter-site Data (IM, App Sharing, etc.)Intra-Site calls, Inter site calls (PSTN Rerouting) Conferencing (IM, Video and Web)Hold, Retrieve, Transfer Presence & DND based routingAuthentication, Authorization Modify Presence or Change Call Forwarding SettingsVoicemail Deposit (Redirect to ExUM in Data Center) Contact ListVoicemail Retrieve (through PSTN) Response Group and Call ParkCall Forwarding, SimulRing, Boss-Admin, Team-callCall Detail Records (CDR)All 2 Party Intra Site communicationsAudio Conferencing through PSTNContact Search
  32. 32. Session Dialog Resiliency• Session Dialog Resiliency (SDR) refers to the ability of a call to resolve and repair a route failure or the temporary inability to reach a remote endpoint• These problems are usually caused by temporary breaks in signaling paths due to intermediate server or temporary remote endpoint connectivity issues• After detecting a break, the signaling layer attempts to locate a new path and re-establish communications.• “Succeed or fail quickly, recover forever”• In the case of a dialog route issue, UMC will resend the message if the dialog can be repaired immediately (a 430 (Flow Failed) response with a “Dialog Route Set Update” header), as shown in the following flow diagram.
  33. 33. Route Resilience• Routes in Lync Server 2010 are a definition of where to send calls that match a specific dial string• Route Resilience• Resiliency for routes is done by providing multiple gateways in a single route, or by creating a redundant route that uses a gateway in a different location• Routes are processed in from a top-to-bottom order so that the priority for a route can specified by adjusting the route placement within the list
  34. 34. Server Draining• Draining a server when preparing it for maintenance• This enables an administrator to prepare a server for maintenance without immediately affecting users• Existing sessions on the server are ended immediately and users will be transferred to a different server within the pool• Preventing new connections is a feature that only works with DNS load balancing• If using a hardware load balancer, perform the draining steps there• This feature does not cover load balancing of the web component services
  35. 35. Start Server Draining e Monitoraggio Connessioni
  36. 36. Lync Audio : FEC e Audio Healing• Forward error correction (FEC) is a method of obtaining error control in data transmission• The source (transmitter) sends redundant data and the destination (receiver) recognizes only the portion of the data that contains no apparent error• In the simplest form of FEC, each character is sent twice• Audio Healing : interpolation
  37. 37. Metropolitan Site Resiliency Solution• Splitting the Front End pool between two physical sites• Topology Builder, these two geographical sites are configured as one single Lync Server 2010 site• Creating separate geographically dispersed clusters (physically separated Windows Server 2008 R2 failover clusters) for • Back End Servers • Group Chat Database Servers • File Servers• Enabling synchronous data replication between the geographically dispersed clusters• Deploying servers running certain server roles in both sites• These roles include Front End Server, A/V Conferencing Server, Director, Edge Server, and Group Chat Server• The servers of each type in both sites are contained within one pool of that type, which crosses both sites• Except for Group Chat Server, all servers of these types, in both sites, are active. For Group Chat Server, only the servers in one site can be active at a time
  38. 38. Metropolitan Site Resiliency Overview
  39. 39. Metropolitan Site Resiliency Prerequisites• All servers that are part of geographically dispersed clusters must be part of the same stretched VLAN, using the same Layer- 2 broadcast domain.• All other internal servers running Lync Server server roles can be on a subnet within that server’s local data center• Edge Servers must be in the perimeter network• Round-trip latency between the two sites must not be greater than 20 ms• Available bandwidth between the sites must be at least 1 Gbps• A geographically dispersed cluster solution based on Windows Server 2008 R2 Failover Clustering must be in place• All geographically dispersed cluster servers must be running the 64-bit edition of Windows Server 2008 R2• All your servers that are running Lync Server must run the Lync Server 2010 version• All database servers must be running the 64-bit edition of one of the following • Microsoft SQL Server 2008 with Service Pack 1 (SP1) (required) or latest service pack (recommended) • Microsoft SQL Server 2008 R2• Both physical and virtual servers are supported
  40. 40. Add : Lync DatabasesContent Topology for the entire Lync deployment (Xds)Management Store(CMS)Pool Configuration Rtc: stores persistent user dataStore Rtcdyn: stores dynamic Lync user data Rtcab1: stores the Lync use address book informationApplication Store Cpsdyn: stores dynamic system information for the Call Park Rgsdyn: stores dynamic runtime operational information for the Call Park application Rgsconfig: stores persistent configuration data for the Response Group applicationArchiving and LcsLog: stores Instant Messaging and Conferencing dataMonitoring Store LcsCdr: stores the Call Details Records QoEMetrics: stores the Quality of Experience dataLocation Store Lync server uses this database (named “lis”) to hold a network ‘wiremap’
  41. 41. Backup Strategy• Backing Up Lync Server Databases • There is nothing unique about the Lync Server databases stored in SQL Server • They can be backed up and restored like any other database.• Backing Up the RTC Database • For a given front end pool, the only database to be backed up is the RTC database • For Monitoring or Archiving services, those databases need to be backed up• Backing Up the Central Management Store • cmdlets for backing up the Central Management Store (CMS) are Export- CsConfiguration and Export-CsLisConfiguration, which export the overall configuration and the E911configuration respectively• Backing Up Lync Server Servers
  42. 42. DEMO : Standard Edition Disaster Recovery
  43. 43. Q&A
  44. 44. Contatti OverNet Education Tel+39 02 365738
  45. 45. Grazie!