Ideas on IT (Infrastructure) vendor selection / How to select an IT (Infrastructure) vendor

This post is about a business aspect of IT Infrastructure. IT vendor selection process is becoming more and more complicated with technology advances and stiff competition between vendors.
Here is sample process I used to pick and choose an IT infrastructure vendor while I was working for a Telecom client.

Architecture Suitability Criteria
 Architecture of the Main Solution
 Architecture of the Backup Solution
 Architecture of the DR Solution
 End of Life (EOL) and End of Support (EOS) of systems
 Platform and System Familiarity

Vendor Suitability Criteria
 Technical Support
 Human Resource pool (Technical)
 Reference Sites
 Past experience with us

Commercial Evaluation Criteria
 Hardware and Implementation
 Maintenance (5 years NPV)
 Implementation Time
 Support & Maintenance Mechanism
 Support for Version Upgrades and New Modules

SAP IT Infrastructure Landscape – Example Design (Cont.)

IT Landscape designing for SAP gains a good experience in IT Infrastructure designing. We can see how some basic designing concepts (like below) behave and work in practice.

• N (Eg:- 3) tier architecture


• N (Eg:- 3) systems landscape


• Application load balancing


• High Availability


• Scalability (Horizontal and Vertical)


• Seamless upgrades and expansions

SAP is a superior ERP product. It has a clear cut guides and best practices in “IT architecture designing, IT architecture sizing”. This is compared to the many other products with no sizing guides, architecture guides.

Nice thing about the SAP’s architecture is that, if you size correctly with future buffers, expanding a SAP IT landscape is seamless. Such an example scenario is given here in this post – “SAP IT Infrastructure Landscape – Example Design”

SAP IT Infrastructure Landscape – Example Design (Cont.) – SAP HW setup after a new acquisition

SAP IT Infrastructure Landscape – Example Design – SAP HW setup for initial phase

Sun (Solaris) Cluster Compliance

Following is the summary for checking Hardware (Server and Storage) compliance for Solaris Cluster.

Server (Hardware) Compliance:-

Sun Servers:-
Most of the Sun servers (even some models of Sun Blades) are supported -http://www.sun.com/software/solaris/cluster/specs.xml

Third party (non Sun) Servers:-
According to “Solaris Cluster Open Hardware Program” -http://www.sun.com/software/cluster/ohp/index.jsp
Only a set of “HP ProLiant x64” are supported - http://www.sun.com/software/cluster/ohp/hp_proliant_interop.jsp
In short “Solaris Cluster is currently not supported on IBM, DELL, Intel servers. Only some of the HP ProLiant x64 servers supported” by November 2009.

Storage (Hardware) Compliance:-

http://www.sun.com/software/solaris/cluster/specs.xml

http://www.sun.com/software/cluster/osp/

Sample set of parameters - Solaris I/O - UFS Tuning

Some of I/O related /etc/system parameters are listed below, This system is a 32GB Solrais x86 server, Always refer to the "SolarisTunable Parameters ReferenceManual" before applying to the systems.

• set maxusers=2048 <- Number of concurrent users on the system determining the amount of physical memory allocated to the kernel (lot of memory and relatively few running processes can save system memory when the default value of maxusers is reduced)
• set ncsize=12000000 <- Defines the number of entries in the directory name look-up cache(DNLC) , use the kstat -n dnlcstats command to determine when entries have been removed from theDNLC because it was too small
• set maxphys=8388608 <- the maximum size of physical I/O requests. If a driver encounters a request larger than this size, the driver breaks the request into maxphys sized chunks
• set pt_cnt=4096 <- When you want to explicitly control the number of users who can remotely log in to the system.
• set npty=176 <- npty limits the number of BSD ptys
• set sadcnt=8192 <- nautopush should be set to twice sadcnt
• set nautopush=4096 <- Set to twice the value of pt_cnt
• set rlim_fd_max=1048576 <- Hard limit on the open file descripters for a single process
• set autoup=600 <- Controls the frequency in seconds of entire physical memory to be scanned for dirty pages
• set tune_t_fsflushr=1 <-Reduces fsflush daemon overhead
• set ufs <-ufs_HW=67108864 <- Limit the amount of I/O that may be outstanding to a single file on a system-wide basis
• set ufs <-ufs_LW=4194304 <- When ufs_HW bytes are outstanding, I/O requests will sleep until less than ufs_LW bytes are outstanding
• set rlim_fd_cur=524288 <- the "soft" limit on file descriptors that a single process can have open
• set segspt_minfree=12500 <- Identifies pages of system memory that cannot be allocated for ISM shared memory
• set maxpgio=65536 <-maximum number of page I/O requests that can be queued by the paging system
• set fastscan=65536 <- maximum number of pages per second that the system looks at when memory pressure is highest
• set segmap_percent=32 <- Amount of memory used, to hold file system pages, % from the physical memory