Everything in pScheduler begins with requesting a test which in turn will be carried-out by a tool. When you run the pscheduler task command the first required argument is the test type and all arguments that follow are dependent on the type of test. The document aims to give you a list of tests and their corresponding tools provided by a default pScheduler installation on perfSONAR. It also tries to give an idea of the options available in each and other important details.
This document highlights the list of test types and tools installed by default when installing pScheduler with perfSONAR. It is possible for others to write their own test and tool plug-ins so this list may not be exhaustive of all tests and tools available.
|Description:||Measure the clock difference between hosts|
|Description:||Measure DNS transaction time|
|Description:||Measure one-way latency and associated statistics between hosts|
|Description:||Continuously measure one-way latency and associated statistics between hosts and report back results periodically|
|Description:||Measure the round trip time and related statistics between hosts|
|Description:||Used primarily for testing, sends a simple “HELLO” message between two hosts using TCP|
|Description:||A test to measure the observed speed of a data transfer and associated statistics between two endpoints|
|Tools:||iperf3, iperf2, nuttcp, bwctliperf3, bwctliperf2|
|Description:||Trace the path between IP hosts|
|Tools:||traceroute, tracepath, paris-traceroute|
Each test classified in one of three categories thatd etermines what other tests can be run in parallel:
- Exclusive - These are tests that cannot run at the same time as any other exclusive or normal test. An example is a throughput test. If you have very little whitespace in this category then you may have difficulty finding a timeslot for new tests.
- Normal - These are tests that can run at the same time as other normal and background tests, but cannot run at the same time as exclusive tests. Currently there are no examples of these in the default test set, but the classification is available for those writing new tools.
- Background - These are tests that can be run in parallel with any other test including exclusive, normal and other background tests. Example test types include latency, latencybg, rtt and trace. It is not uncommon to have this column look almost entirely solid if you have latencybg tests since they run continuously. Since these runs do not prevent other runs from executing though, they should not limit your ability to schedule new tests.
Throughput tests support the following arguments:
pscheduler task throughput --help Usage: task [task-options] throughput [test-options] -h, --help show this help message and exit -s SOURCE, --source=SOURCE Sending host --source-node=SOURCE_NODE pScheduler node on sending host, if different -d DESTINATION, --dest=DESTINATION, --destination=DESTINATION Receiving host --dest-node=DEST_NODE pScheduler node on receiving host, if different -t DURATION, --duration=DURATION Total runtime of test -i INTERVAL, --interval=INTERVAL How often to report results (internally, results still reported in aggregate at end) -P PARALLEL, --parallel=PARALLEL How many parallel streams to run during the test -u, --udp Use UDP instead of TCP testing -b BANDWIDTH, --bandwidth=BANDWIDTH Bandwidth to rate limit the test to, supports SI notation such as 1G -w WINDOW_SIZE, --window-size=WINDOW_SIZE TCP window size to use for the test, supports SI notation such as 64M -m MSS, --mss=MSS TCP maximum segment size -l BUFFER_LENGTH, --buffer-length=BUFFER_LENGTH length of the buffer to read/write from --ip-tos=IP_TOS IP type-of-service octet (integer) --ip-version=IP_VERSION Specify which IP version to use, 4 or 6 -B LOCAL_ADDRESS, --local-address=LOCAL_ADDRESS Use this as a local address for control and tests -O OMIT, --omit=OMIT Number of seconds to omit from the start of the test --no-delay Set TCP no-delay flag, disables Nagle's algorithm --congestion=CONGESTION Set TCP congestion control algorithm --zero-copy Use a 'zero copy' method of sending data --flow-label=FLOW_LABEL Set the IPv6 flow label, implies --ip-version 6 --client-cpu-affinity=CLIENT_CPU_AFFINITY Set's the sending side's CPU affinity --server-cpu-affinity=SERVER_CPU_AFFINITY Set's the receiving's side's CPU affinity --reverse Reverses the direction of the test.
The currently supported throughput tools are iperf2, iperf3, and nuttcp. iperf3 is the default. Note that not every tool supports every option. The following table summarizes tool specific option. Other pScheduler options are supported by all tools.
Latency tests support the following arguments:
pscheduler task latency --help Usage: task [task-options] latency [test-options] -h, --help show this help message and exit -s SOURCE, --source=SOURCE The address of the entity sending packets in this test --source-node=SOURCE_NODE The address of the source pScheduler node, if different -d DEST, --dest=DEST The address of the entity receiving packets in this test --dest-node=DEST_NODE The address of the destination pScheduler node, if different -c PACKET_COUNT, --packet-count=PACKET_COUNT The number of packets to send -i PACKET_INTERVAL, --packet-interval=PACKET_INTERVAL The number of seconds to delay between sending packets -L PACKET_TIMEOUT, --packet-timeout=PACKET_TIMEOUT The number of seconds to wait before declaring a packet lost -p PACKET_PADDING, --packet-padding=PACKET_PADDING The size of padding to add to the packet in bytes -C CTRL_PORT, --ctrl-port=CTRL_PORT The port to use for making a control connection to the side acting as a server. -P DATA_PORTS, --data-ports=DATA_PORTS The port range to use on the side of the test running the client. At least two ports required. -T IP_TOS, --ip-tos=IP_TOS The port range to use on the side of the test running the client. At least two ports required. --ip-version=IP_VERSION Force an IP version when performing the test. Useful when specifying hostnames as source or dest that may map to both IPv4 and IPv6 addresses. -b BUCKET_WIDTH, --bucket-width=BUCKET_WIDTH The bin size to use for histogram calculations. This value is divided into the result as reported in seconds and truncated to the nearest 2 decimal places. -f, --flip In multi-participant mode, have the dest start the client and request a reverse test. Useful in some firewall and NAT environments. -R, --output-raw Output individual packet statistics. This will substantially increase the size of a successful result.
RTT tests support the following arguments:
pscheduler task rtt --help Usage: task [task-options] rtt [test-options] -h, --help show this help message and exit --count=COUNT Test count --dest=DEST Destination host --flow-label=FLOW_LABEL Flow label --hostnames Look up hostnames from IPs --no-hostnames Don't look up hostnames from IPs --interval=INTERVAL Time to wait between packets sent --ip-version=IP_VERSION IP version to use --source=SOURCE Source address or interface --source-node=SOURCE_NODE Source pScheduler node, if different --suppress-loopback Suppress multicast loopback --no-suppress-loopback Don't suppress multicast loopback --ip-tos=IP_TOS IP type-of-service octet (integer) --length=LENGTH Packet length --ttl=TTL Time to live --deadline=DEADLINE Deadline for all measurements to complete --timeout=TIMEOUT Timeout for each round trip