pmproxy

Langue: en

Autres versions - même langue

Version: SGI (fedora - 01/12/10)

Section: 1 (Commandes utilisateur)

NAME

pmproxy - proxy for performance metrics collector daemon

SYNOPSIS

pmproxy [-f] [-i ipaddress] [-l logfile] [-L bytes] [-U username] [-x file]

DESCRIPTION

pmproxy acts as a protocol proxy for pmcd(1), allowing Performance Co-Pilot (PCP) monitoring clients to connect to one or more pmcd(1) instances via pmproxy.

Normally pmproxy is deployed in a firewall domain, or on a ``head'' node of a cluster where the IP (Internet Protocol) address of the hosts where pmcd(1) is running may be unknown to the PCP monitoring clients, although the IP address of the host where pmproxy is running is known to these clients. Similarly, the clients may have network connectivity only to the host where pmproxy is running, while there is network connectivity from that host to the hosts of interest where pmcd(1) is running.

The behaviour of the PCP monitoring clients is controlled by either the PMPROXY_HOST environment variable or through the extended hostname specification (see PCPIntro(1) for details). If neither of these mechanisms is used, clients will make their connections directly to pmcd(1). If the proxy hostname syntax is used or PMPROXY_HOST is set, then this should be the hostname or IP address of the system where pmproxy is running, and the clients will connect to pmcd(1) indirectly through the protocol proxy services of pmproxy.

The options to pmproxy are as follows.

-f
By default pmproxy is started as a daemon. The -f option indicates that it should run in the foreground. This is most useful when trying to diagnose problems with establishing connections.
-i ipaddress
This option is usually only used on hosts with more than one network interface (very common for firewall and ``head'' node hosts where pmproxy is most likely to be deployed). If no -i options are specified pmproxy accepts PCP client connections on any of its host's IP addresses. The -i option is used to specify explicitly an IP address that PCP client connections should be accepted on. ipaddress should be in the standard dotted form (e.g. 100.23.45.6). The -i option may be used multiple times to define a list of IP addresses. When one or more -i options is specified, attempted connections made on any other IP addresses will be refused.
-l logfile
By default a log file named pmproxy.log is written in the current directory. The -l option causes the log file to be written to logfile instead of the default. If the log file cannot be created or is not writable, output is written to the standard error instead.
-L bytes
PDUs received by pmproxy from PCP monitoring clients are restricted to a maximum size of 65536 bytes by default to defend against Denial of Service attacks. The -L option may be used to change the maximum incoming PDU size.
-U username
Assume the identity of username before starting to accept incoming packets from PCP monitoring clients.
-x file
Before the pmproxy logfile can be opened, pmproxy may encounter a fatal error which prevents it from starting. By default, the output describing this error is sent to /dev/tty but it may redirected to file.

STARTING AND STOPPING PMPROXY

Normally, pmproxy is started automatically at boot time and stopped when the system is being brought down (see rc2(1M) and rc0(1M)). Under certain circumstances it is necessary to start or stop pmproxy manually. To do this one must become superuser and type

# $PCP_RC_DIR/pmproxy start

to start pmproxy, or

# $PCP_RC_DIR/pmproxy stop

to stop pmproxy. Starting pmproxy when it is already running is the same as stopping it and then starting it again. Normally pmproxy listens for PCP client connections on TCP/IP port number 44322 (registered at http://www.isecom.info). The environment variable PMPROXY_PORT may be used to specify an alternative port number. If PMPROXY_PORT is used, care should be taken to ensure the environment variable is set before pmproxy is started.

FILES

PCP_PMPROXYOPTIONS_PATH
command line options and environment variable settings for pmproxy when launched from PCP_RC_DIR/pmproxy All the command line option lines should start with a hyphen as the first character. This file can also contain environment variable settings of the form "VARIABLE=value".
./pmproxy.log
(or PCP_LOG_DIR/pmproxy/pmproxy.log when started automatically)
All messages and diagnostics are directed here

ENVIRONMENT

In addition to the PCP environment variables described in the PCP ENVIRONMENT section below, there are several environment variables that influence the interactions between a PCP monitoring client, pmcd and pmcd(1).
PMCD_PORT
For the PCP monitoring client this (or the default port number) is passed to pmproxy and used to connect to pmcd(1). In the environment of pmproxy PMCD_PORT is not used.
PMPROXY_HOST
For the PCP monitoring client this is the hostname or IP address of the host where pmproxy is running. In recent versions of PCP (since version 3) this has been superceded by the extended hostname syntax (see PCPIntro(1) for details).
PMPROXY_PORT
For the PCP monitoring client this is the port on which pmproxy will accept connections. The default is 44322.
PMCD_CONNECT_TIMEOUT, PMCD_RECONNECT_TIMEOUT and PMCD_REQUEST_TIMEOUT
(see PCPIntro(1)) For the PCP monitoring client, setting these environment variables will modify the timeouts used for interactions between the client and pmproxy (independent of which pmcd(1) is being used). For pmproxy these same environment variables control the timeouts between pmproxy and all pmcd(1) instances (independent of which monitoring client is involved).

PCP ENVIRONMENT

Environment variables with the prefix PCP_ are used to parameterize the file and directory names used by PCP. On each installation, the file /etc/pcp.conf contains the local values for these variables. The PCP_CONF variable may be used to specify an alternative configuration file, as described in pcp.conf(4).

SEE ALSO

PCPIntro(1), pmcd(1), pmdbg(1), pcp.conf(4) and pcp.env(4).

DIAGNOSTICS

If pmproxy is already running the message "Error: OpenRequestSocket bind: Address already in use" will appear. This may also appear if pmproxy was shutdown with an outstanding request from a client. In this case, a request socket has been left in the TIME_WAIT state and until the system closes it down (after some timeout period) it will not be possible to run pmproxy.

In addition to the standard PCP debugging flags, see pmdbg(1), pmproxy currently uses DBG_TRACE_CONTEXT for tracing client connections and disconnections