HV Stufe 2: Parallel Sysplex

Transcription

1 Hanseatic Mainframe Summit 200 Mittwoch,. September 200 HV Stufe 2: arallel Sysplex Martin Söllig Availability artitioned Shared Coupling Technologie Shared Data - Ständige Anwendungsverfügbarkeit

2 Scalability artitioned Shared Coupling Technologie Shared Data - Unterbrechungsfreies schrittweises Wachstum Basic shared DASD zseries ( or LAR) zseries ( or LAR) channels channels Real system would have many more control units and devices control unit control unit Limited capability Reserve and release against a whole disk Limits access to that disk for the duration of the update

3 GRS Ring zseries ( or LAR) zseries ( or LAR) channels CTC channels CTC control unit control unit Can have more systems in the CTC"ring" Global Resource Sharing (GRS) used to pass information between systems via the CTC ring Request ENQueue on a dataset, update, the DEQueue Loosely coupled system arallel Sysplex system or LAR Coupling Facility zseries ( or LAR) CF channels zseries ( or LAR) channels channels control unit control unit This extension of the CTC ring uses a dedicated Coupling Facility to store ENQ data for GRS This is much faster The CF can also be used to share application data such as DB2 tables Can appear as a single system

4 arallel Sysplex hysische Sicht Logische Sicht Coupling Technologie Dynamisches Workload Balancing 7 5 Sysplex Timer ESCON 672 A L A L A L A L Appl Application Coupling Facility Shared data Data Sharing Redundanz im arallel Sysplex Doppelte Coupling Facility Coupling Facility Coupling Facility C C N C C N Redundante Links C CEC C N Redundante Timer C CEC N C N DASD ESCON Director Remote Copy ESCON Director N DASD Kein Single oint of Failure

5 System z Continuous Availability Single System arallel Sysplex GDS Built In Redundancy Capacity Upgrade on Demand Capacity Backup Hot luggable I/O to 32 Systems Addresses lanned / Unplanned Hardware / Software Outages Flexible, Non-disruptive Growth - Capacity beyond largest CC - Scales better than SMs Dynamic Workload/Resource Management Site Site 2 Addresses Site Failure and Site Maintenance Disk / Tape Remote Copy - Eliminates SOF - No / Some Data Loss Application Independent arallel Sysplex rovides for a single system image from several perspectives: Data access, allowing dynamic workload balancing and improved availability Dynamic Transaction Routing, providing dynamic workload balancing and improved availability End-user interface, allowing logon to a logical network entity Operational interfaces, allowing easier Systems Management to 32 Systems

6 arallel Sysplex At the heart of a arallel Sysplex, there is (at least one) Coupling Facility. It is used for three purposes: Locking information that is shared among all attached systems Cache information (such as for a database) that is shared among all attached systems Data list information that is shared among all attached systems to 32 Systems arallel Sysplex Scalability (allows granular growth) Flexibility of workload Continuous availability laned outages (of a single system) HW maintanance (repair, upgrade) SW maintanance (atches, fixes, release upgrades) with IL Unplanded outages HW problems SW problems Workload Management SLA Members (LARs) of a arallel Sysplex can can reside on one or multiple machines Members (LARs) of a arallel Sysplex can reside in one or multple sites Sites can have a distance of about up to 00 km (cross-site) Members (LARs) of a arallel Sysplex can run on different hardware or software releases! to 32 Systems

7 arallel Sysplex Data sharing and Coupling facility Data Integrity in a arallel Sysplex Cluster REQUESTS REQUESTS LOCKS DATABASE MANAGER DATA BUFFERS Multi-System Serialization Changed Data DATA BUFFERS DATABASE MANAGER LOCKS zseries Sysplex Services Coupling Technology zseries Locks Directories Caches

8 arallel Sysplex Software Structure Batch Job OLT WEB crossplatform VTAM TC/I MQ Single System Image & High Availability Connections Batch Transaction Managers CICS TSO IMS Dynamic Workload Balancing Appl Appl Appl Appl Appl Appl Applications Unchanged IMS DB DB2 RLS,TVS Oracle Adaplex IDMS Datacom Data Managers Data Sharing Base Services Hardware Interfaces CICS Transaction Server NETWORK ARM Support for Data Sharing Servers (V2.) VTAM - A Comm Server TOR CSM TC/I - B Comm Server TOR CSM Named Counter servers Coupling Facility data table server Shared Temporary Storage server System Managed Duplex & Rebuild support (V2.2) Sign-On Retention for ersistent Sessions (V2.2) DB2 Group Attach (V2.2) AOR CF AOR Batch logging of VSAM data (SOD for CICSVR) Support for DB2V Restart Light (V2.3) SMSVSAM SMSVSAM Systems management enhancements in (V2.3) Improved Application Availability

9 z6 Coupling Links Fanout, not I/O slot, used for InfiniBand ICB-4 No longer supported ETR No longer supported All coupling links support ST Sysplex Coexistence z0 EC and BC and z EC and BC only HCA2-O HCA2-O LR 2x InfiniBand Up to 50 meters x InfiniBand DDR Up to 0/00 Km 2x InfiniBand SDR z6, z0 EC, z0 BC Up to 50 meters z EC and z BC HCA2-O Fanouts HCA2-C IFB-M ISC-3 ISC-3 ISC-3 ISC-3 ISC-3 Up to 0/00 km z6 I/O Drawer or I/0 Cage z6, z0 EC, z0 BC, z EC, z BC z6tllb7 ST Design oint Concept ST supports configurations up to Stratum 3 Stratum ST transmits timekeeping information in layers or Stratums Stratum Highest level in the hierarchy of timing network that uses ST to synchronize to CST Stratum 2 Server/Coupling Facility (CF) that uses ST messages to synchronize to Stratum Stratum 3 Server/Coupling Facility (CF) that uses ST messages to synchronize to Stratum 2 Stratum 2 Stratum 2 ST supports configurations up to S3 Stratum 3 Stratum 3

10 No Support for ETR with z6 Use Mixed CTN Sysplex Timer ETR ID = XX CLO Link Sysplex Timer ETR ID = XX ETR Link System z/z0 Stratum System z/z0 Stratum CF Link z6 Stratum 2 HMC Ethernet Switch z6 Stratum 2 z6 DOES NOT support ETR. It is possible to have a z6 server as a Stratum 2 or Stratum 3 server in a Mixed CTN as long as there are at least two z0s or zs attached to the Sysplex Timer operating as Stratum servers Two Stratum servers are recommended but not required to provide redundancy and avoid a single point of failure Suitable for a customer planning to migrate to an ST-only CTN. z6tllb ST-Only CTN with z6 External Time Source (ETS) HMC Configuration has to be defined Must assign TS and CTS Optionally assign BTS Strongly recommended to allow near-continuous availability Optionally assign Arbiter Recommended for configurations of 3 or more servers/cfs Can improve recovery z6 Ethernet Switch z0 EC ST can use coupling links z6 can be any one (or all) of the servers z EC z6 z6 z6tllb20

11 Create a redundant I/O configuration LARn LAR2 LAR LARn LAR2 LAR CSS / CHID Director (Switch) DASD CU DASD CU... IBM HA / CA technology solutions CA at System z level - arallel Sysplex and Data Sharing: Having a minimum of 2 Logical artitions running on 2 different System z boxes, and having the same application running in parallel in these LARs and sharing the data and the control information in a Coupling Facility, together with a frontend dynamic workload balancing mechanism can bring a high level of availability. Typical example of such an architecture: Sysplex Timer IBM System z unique System z LAR LAR2 LAR3 System z No SoF if the application can run everywhere (in any of the 3 partitions no affinity). CF

12 IBM HA / CA technology solutions Configure the arallel Sysplex for system availability: Run with cloned systems and applications Maintain all systems at the same release and maintenance levels Deploy redundant components Install enough capacity to accommodate failures Exploit Global Resource Serialization (GRS) Star Exploit Virtual I Addressing (VIA) Implement Workload Manager policies (WLM) Exploit Automatic Restart Manager (ARM) Exploit Sysplex Failure Management (SFM) Implement data sharing, transaction routing, queue sharing Implement Health Checker Implement data replication z EC Coupling Facility Sysplex Timer or ST FICON switch z0 z0 Metro Mirror Shared Data