Network Performance: An MPE/iX Overview Jeff Bandle HP MPE/iX Networking Architect
CONTENTS • General Networking – – • MPE/iX Specific Networking – – • Common networking terms Networking concepts independent of MPE/iX Overview of MPE/iX networking stacks Ideas for performance changes on MPE/iX System Performance – 11/13/2008 How MPE/iX networking performance affects the system HP presentation template user tutorial page 2
INTRODUCTION • What is performance? – – – • Bandwidth Response time System General Networking vs.
GENERAL NETWORKING • Network – setup complexity is a factor Simple Network – Fewer layers to propagate data e3000 DTC Terminal 11/13/2008 HP presentation template user tutorial Printer page 4
GENERAL NETWORKING • Network setup complexity – – Complex network – More layers/hardware delays data propagation Study of “pings” to 3000 international sites – 150 ms avg.
GENERAL NETWORKING • Use or Routers, Switches and Hubs – Hub - – Switch - – Router - A hub is a small, simple, inexpensive device that joins multiple computers together at a low-level network protocol layer. A switch is a small device that joins multiple computers together at a lowlevel network protocol layer. Technically, switches operate at layer two (Data Link Layer) of the OSI model. A router is a physical device that joins multiple networks together.
GENERAL NETWORKING • Common tools to check complex networking – Ping ping [-oprv] [-i address] [-t ttl] host packet-size [[-n] count] : ping nack.cup.hp.com PING nack.cup.hp.com: 64 byte packets 64 bytes from 15.13.195.50: icmp_seq=0. 64 bytes from 15.13.195.50: icmp_seq=1. 64 bytes from 15.13.195.50: icmp_seq=2. 64 bytes from 15.13.195.50: icmp_seq=3. 64 bytes from 15.13.195.50: icmp_seq=4. 64 bytes from 15.13.195.50: icmp_seq=5. 64 bytes from 15.13.195.50: icmp_seq=6. 64 bytes from 15.13.195.
GENERAL NETWORKING • Common tools to check complex networking – Traceroute traceroute [-dnrv] [-w wait] [-m max_ttl] [-p port#] [-q nqueries] [-s src_addr] host [data size] traceroute to cup.hp.com (15.75.208.53), 30 hops max, 20 byte packets 11/13/2008 1 cup47amethyst-oae-gw2.cup.hp.com (15.244.72.1) 1 ms 1 ms 1 ms 2 hpda.cup.hp.com (15.75.208.
GENERAL NETWORKING • Traceroute (cont) traceroute to atl.hp.com (15.45.88.30), 30 hops max, 20 byte 1 cup47amethyst-oae-gw2.cup.hp.com (15.244.72.1) 1 ms 2 cup44-gw.cup.hp.com (15.13.177.65) 1 ms 3 cupgwb01-legs1.cup.hp.com (15.61.211.71) 1 ms 4 palgwb02-p7-4.americas.hp.net (15.243.170.45) 2 ms 5 atlgwb02-p6-1.americas.hp.net (15.235.138.17) 60 ms 6 atlgwb03-vbb102.americas.hp.net (15.227.140.7) 60 ms 7 atldcrfc5.tio.atl.hp.com (15.41.16.205) 61 ms 8 i3107at1.atl.hp.com (15.45.88.
GENERAL NETWORKING • Traceroute (cont) traceroute to www-dev.bri.hp.com (15.144.120.100), 30 hops max, 20 byte packets 1 cup47amethyst-oae-gw2.cup.hp.com (15.244.72.1) 1 ms 1 ms 1 ms 2 cup44-gw.cup.hp.com (15.13.177.65) 1 ms 1 ms 1 ms 3 cupgwb01-legs1.cup.hp.com (15.61.211.71) 1 ms 1 ms 1 ms 4 palgwb02-p7-4.americas.hp.net (15.243.170.45) 2 ms 2 ms 1 ms 5 atlgwb02-p6-1.americas.hp.net (15.235.138.17) 60 ms 60 ms 61 ms 6 15.227.138.42 (15.227.138.42) 183 ms 204 ms 183 ms 7 bragwb02.europe.hp.net (15.203.
GENERAL NETWORKING • Hardware Potential Performance Changes – Routers – • Use router tools to analyze networking traffic • Readjust traffic loads to balance across different connections (if possible) • Use tools to verify memory usage is not being compromised for connections 11/13/2008 HP presentation template user tutorial page 11
GENERAL NETWORKING • Hardware Potential Performance Changes – Routers – • Since routers have intelligence inside of them, data is stored in buffers • Common performance problems related to buffer allocation Middle buffers, 600 bytes (total 150, permanent 25): 147 in free list (10 min, 150 max allowed) 61351931 hits, 137912 misses, 51605 trims, 51730 created 91652 failures (0 no memory) – permanent: take the number of total buffers in a pool and add about 20%.
GENERAL NETWORKING • Hardware Potential Performance Changes – Switches • Dependant on type and brand, changeable parameters vary – Change speed (10/100/1000 mbps) to match other devices – Change Duplex level (Half/Full to relieve conflicts) – Autonegotiation isnt’ full foolproof (If possible nail port paramters) – Link multiple ports together in a trunk (not all switches) – Limited to direct connections with peer switch 11/13/2008 HP presentation template user tutorial page 13
GENERAL NETWORKING • Hardware Potential Performance Changes – Hubs • Hubs usually don’t have parameters that can be changed for performance • If they are bundled with a switch, use switch information to make changes • Most hubs, by default, are half-duplex in operation – Need to validate that connections into the hub are half duplex 11/13/2008 HP presentation template user tutorial page 14
GENERAL NETWORKING • Other Potential Issues – Difference in software standards • HTTP 1.0 vs. HTTP 1.1 – Persistent connections • Large data frames – Not standard in all hardware – Systems need to work to keep “pipes” full • Introduction of Fiberchannel starting to push 100BT • Other – places for tips and tricks www.web100.org - Pointers to tools for performance analysis www.compnetworking.about.com – High level info on networks – www.practicallynetworked.
MPE/iX SPECIFIC NETWORKING • MPE/iX Networking Stacks Made of Multiple Layers F Intrinsics Sockets/Net IPC APIs ADCP Telnet AFCP TCP/IP/UDP Network Links 11/13/2008 HP presentation template user tutorial page 16
MPE/iX SPECIFIC NETWORKING • MPE/iX – Networking Stack – Links 100BT/100VG – Full Duplex vs. Half Duplex • Full Duplex allows for send and receive traffic at the same time • 100 VG had some advantages but lost out on marketing side VHS vs.
MPE/iX SPECIFIC NETWORKING • MPE/iX – Networking Stack – Links ACC – WAN Link • Speeds limited by connection medium – Phone speeds and satellite technologies – 2 mbps possible • Best used as an access point into a network, not as interconnect between systems.
MPE/iX SPECIFIC NETWORKING • MPE/iX Networking Stack – Transports • AFCP – Used to communicate with DTC device – HP Proprietary – Configuration within NMMGR to change parameters – After selecting DTC to configure, select TUNE DTC option Set 1: Normal timer mode Set 2: Short retransmission timer mode Set 3: Long retransmission timer mode Set 4: Variable timer mode Set 5: MPE XL Release 1.2 timer mode Set 6: MPE XL Release 2.
MPE/iX SPECIFIC NETWORKING • MPE/iX Networking Stack – Transports • TCP/IP – Used to communicate with open standards based devices – Configuration with NMMGR – Within the NS->UNGUIDED CONFIG->NETXPORT->GPROT->TC [1024] Maximum Number of Connections [2] Retransmission Interval Lower Bound (Secs) [180] Maximum Time to Wait For Remote Response (Sec) [4] Initial Retransmission Interval (Secs) [4] Maximum Retransmissions per Packet [600 ] Connection Assurance Interval (Secs) [4 ] 11/13/2008 Maximum Connectio
MPE/iX SPECIFIC NETWORKING • MPE/iX – Networking Stack – APIs Sockets – Standards based networking connectivity interface • Sending data requires use of data buffers • Tradeoff between efficiency in application and efficiency in networking • Studies seem to point to 1k byte buffers being optimal balance • Only works if application can package data.
MPE/iX SPECIFIC NETWORKING • MPE/iX – Networking Stack – APIs NetIPC – HP Propriety networking connectivity interface • Similar to open standards sockets • 1k byte buffers are optimal if application allows • Fix length data blocks remove need to negotiate buffer length – Eliminates an extra IPCRECEIVE call for get length of data • Connection startup/teardown is expensive – AVOID IF POSSIBLE 11/13/2008 HP presentation template user tutorial page 22
MPE/iX SPECIFIC NETWORKING • MPE/iX – Networking Stack – Services Telnet – Open standards terminal connectivity • Based on very inefficient 1-character transfer mode • Most common complaint is character echo response • Block mode response is comparable to VT/DTC • Character echo improved with Advanced Telnet functionality – Requires terminal emulator that supports it.
MPE/iX SPECIFIC NETWORKING • MPE/iX – Networking Stack – Services DTC TIO/ADCP – HP Proprietary terminal connectivity • Efficient block mode data transfer • Higher cost due to needing DTCs and special applications • DTSTUNEB can be used to adjust buffer parameters – WARNING – Due so at your own risk.
MPE/iX SYSTEM PERFORMANCE to NETWORKING • Networking – – – – connections use resources Data structures for each socket/NetIPC connection Data buffers for each DTC/Telnet connection Timer structures used by all layers Busy connections on small systems can exhaust resources • “Fake” system by creating more “dummy” devices 11/13/2008 HP presentation template user tutorial page 25
MPE/iX SYSTEM PERFORMANCE to NETWORKING • System – is very busy servicing interrupts Tradeoff between “smart” cards and “dumb” cards • Network adapters could do more work • Newer cards are cheaper, but system needs to do processing • High LAN traffic situations see this more often as problem • Solution is to get more CPU • Efficiencies have been introduced into MPE/iX stacks 11/13/2008 HP presentation template user tutorial page 26
MPE/iX SYSTEM PERFORMANCE to NETWORKING • Connectivity – mix can affect system performance VT vs. DTC vs.
MPE/iX SYSTEM PERFORMANCE to NETWORKING • Connectivity mix can affect system performance (cont) • Telnet is least efficient because of need to support open standards – Block mode applications (VPLUS) comparable to VT – Telnet is 90% as efficient as VT in block mode – CI commands most overhead for Telnet – 1 character at a time response – Telnet is 70% as efficient as VT in character mode 11/13/2008 HP presentation template user tutorial page 28
MPE/iX SYSTEM PERFORMANCE to NETWORKING • Check – – for application type with regards to I/O Block mode access vs.
MPE/iX SYSTEM PERFORMANCE to NETWORKING • Check – – – for application type with regards to I/O (cont) Check to see how networking connections are being made Multiple starts/shutdowns for connection are EXPENSIVE On small 918 class system, 15 user test FAFFed system • Higher CPU • Different connectivity methods • More memory 11/13/2008 HP presentation template user tutorial page 30
WRAPUP • If you suspect networking performance problems, what can you do? – – Characterize problem – can’t connect, lost packets, system is bogging down Understand where heaviest use is coming from • Single application use – Can application/parms be tweaked to ease performance pressure? • Multiple users rapidly connecting to system – Can users be directed to connect by differing methods • Network is experiencing problems – Isolate segment that is causing problem – Check router, switch for potential
