You there? Yes Network Health Monitoring • Heartbeats are sent to monitor health status of network interfaces • Are sent over all cluster enabled networks Intra-cluster Communication CSV I/O.
Download ReportTranscript You there? Yes Network Health Monitoring • Heartbeats are sent to monitor health status of network interfaces • Are sent over all cluster enabled networks Intra-cluster Communication CSV I/O.
You there? Yes Network Health Monitoring • Heartbeats are sent to monitor health status of network interfaces • Are sent over all cluster enabled networks Intra-cluster Communication CSV I/O Redirection • Database updates and state synchronization that are sent between the nodes in the cluster • Example: When creating a new resource the cluster database must be updated on all nodes • Are over a single interface • Metadata updates to files • All I/O in failure scenarios • Over same network as intra-cluster communication • Over a single interface • Can leverage SMB multichannel to stream over multiple interfaces Heartbeats • Lightweight (only 134 bytes) • Sensitive to latency • If cluster heartbeats become blocked by a saturated NIC, this could cause nodes to be removed from cluster membership • Bandwidth not important, but quality of service is Intra-Cluster Communication • Lightweight • Traffic varies by workload, in general infrequent on running stable File / Hyper-V clusters. Heavier on SQL / Exchange clusters • Clustering is a distributed synchronous system, latency will slow down cluster state changes (such as failover) • Bandwidth not important, but quality of service is CSV I/O Redirection • Metadata updates • Lightweight and Infrequent • Latency will slow down I/O performance • Yes, network performance will impact storage I/O performance! • Quality of service most important • Failure scenarios / asymmetric storage configurations • All I/O is forwarded via SMB over the network • Network bandwidth is most important I can’t get through! Key Take-away: Primary design consideration for cluster communication is ensuring quality of service 1 2 3 Host Management Virtual Machines Live Migration 4 Intra-cluster communication / CSV 5 iSCSI •Isolated network for the host partition •Increased security isolation (could use VLAN’s to isolate from Client network) •Public network for client access to VMs •Short duration heavy burst traffic •Intra-cluster communication is lightweight, but sensitive to latency •Metadata updates are infrequent and light, but failure conditions could be heavy •Dedicated storage network •Disable for cluster use Key Takeaway: It is really about providing quality of service guarantees!! Required? • No – It is not required to have 2 separate networks • Clustering does support a converged networking model • Validate will generate a Warning to alert you of a potential single point of failure • Validate is not NIC Teaming aware Recommended? • Yes – It is recommended to have redundant network communication between nodes • Sort of… let’s talk about what really matters and converged networking (next slide) Resiliency I/O Redirected via SMB VM running on Node 2 is unaffected SAN SAN Connectivity Failure • Consideration: Highest Availability Tolerance of Transient Failures Property Default Maximum Description SameSubnetDelay 1 second 2 seconds Frequency heartbeats are sent SameSubnetThreshold 5 heartbeats 120 heartbeats Missed heartbeats before an interface is considered down CrossSubnetDelay 1 second 4 seconds Frequency heartbeats are sent to nodes on dissimilar subnets CrossSubnetThreshold 5 heartbeats 120 heartbeats Missed heartbeats before an interface is considered down to nodes on dissimilar subnets Increasing heartbeat thresholds does not fix network problems, it only masks them! Cluster Property Default Hyper-V Default SameSubnetThreshold 5 10 CrossSubnetThreshold 5 20 Name Value Description Disabled for Cluster Communication 0 No cluster communication of any kind sent over this network Enabled for Cluster Communication only 1 Internal cluster communication and CSV traffic can be sent over this network Enabled for client and cluster communication 3 Cluster IP Address resources can be created on this network for clients to connect to. Internal and CSV traffic can be sent over this network Disabled for Cluster • If enabled for iSCSI Software Initiator Communication • New Windows Server 2012 logic Enabled for Cluster Communication only Enabled for client and cluster communication • If no default gateway is present • If a default gateway is present http://blogs.msdn.com/b/virtual_pc_guy/archive/2013/05/02/using-powershell-toconfigure-live-migration-networks-in-a-hyper-v-cluster.aspx 10.10.10.X 20.20.20.X CSV Streaming I/O Across Multiple Networks Prioritization Bandwidth Allocation • Recommendation: Configure on all cluster deployments • Heartbeats and Intra-cluster communication are sensitive to latency and configuring a QoS Priority Flow Control policy will ensure they are sent first • Recommendation: Configure on CSV deployments • CSV may send large amounts of data, need to ensure it has sufficient bandwidth • Relative Minimum Bandwidth SMB policy recommended Do not attempt to find cross subnet routes if local routes are found Always attempt to find routes that cross subnets Disable the cluster service from attempting to discover cross subnet routes after node successfully joins Network Name Resource OR OR IP Address Resource A IP Address Resource B DNS Replication DNS Server 1 Record Created Record Updated 10.10.10.111 20.20.20.222 Site A Site B DNS Server 2 Record Obtained Record Updated DNS Server 1 10.10.10.111 20.20.20.222 VM = 10.10.10.111 Site A Site B DNS Server 2 DNS Server 1 10.10.10.111 10.10.10.111 VLAN FS = 10.10.10.111 Site A Site B http://www.cisco.com/en/US/docs/solutions/Enterprise/Data_Center/App_Networking/extmsftw2k8vistacisco.pdf DNS Server 2 30.30.30.30 DNS Server 1 10.10.10.111 20.20.20.222 VM = 30.30.30.30 Site A Site B • RegisterAllProvidersIP • HostRecordTTL • Disclaimer: This does not speed up DNS replication Value Description 0 Clear Text 1 Signed (default) 2 Encrypted Disclaimer: Incurs some performance overhead Site A Site B 10.10.10.1 30.30.30.1 20.20.20.1 40.40.40.1 Property Description ResourceData Resource Internal Use (read only) StatusNetBIOS Status (error) code for NetBIOS – 0 means no error (read only) StatusDNS Status (error) code for DNS – 0 means no error (read only) StatusKerberos Status (error) code for Kerberos – 0 means no error (read only) CreatingDC Domain controller upon which this netname’s AD object was initially created (read only) LastDNSUpdateTime Time at which DNS was last updated (read only) ObjectGUID (read only) Name The name published in NetBIOS and SAM account name in AD DnsName The name published in DNS RemapPipeNames Legacy setting for SMB HostRecordTTL TTL in seconds of the DNS record, this controls how long caches will retain the record RegisterAllProvidersIP 0 (false), 1 (true) – when enabled all IP addresses this netname depends on will be published to DNS no matter what their provider state is PublishPTRRecords 0 (false), 1 (true) – Create reverse DNS records TimerCallbackAdditionalThreshold Unused Property Description LeaseObtainedTime Time when DHCP lease was acquired (Read only) LeaseExpiresTime Time when DHCP lease runs out (Read only) DhcpServer The DHCP server that issued the lease (Read only) DhcpAddress Address assigned by DHCP (Read only) DhcpSubnetMask Subnet mask assigned by (Read only) Network The network this IP address is on (such as “Cluster Network 2”) Address The IP Address assigned to this IP resource SubnetMask Subnet mask EnableNetBIOS 0 (false), 1 (true) - Controls whether this address is published by netbios OverrideAddressMatch This setting is unused EnableDhcp 0 (false), 1 (true) – determines whether this IP Address resource obtains its address via DHCP http://aka.ms/WS2012R2 http://aka.ms/SC2012R2 http://channel9.msdn.com/Events/TechEd www.microsoft.com/learning http://microsoft.com/technet http://microsoft.com/msdn