pmproxy - proxy for performance metrics collector
daemon
pmproxy [-Aft] [-C dirname] [-i
ipaddress] [-l logfile] [-L bytes]
[-M certname] [-p port[,port ...]
[-P passfile] [-U username] [-x
file]
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.
- -A
- Disable service advertisement. By default, pmproxy will advertise
its presence on the network using any available mechanisms (such as
Avahi/DNS-SD), assisting remote monitoring tools with finding it. These
mechanisms are disabled with this option.
- -C dirname
- Specify the path to the Network Security Services certificate database,
for (optional) secure connections. The default is /etc/pki/nssdb.
Refer also to the -P option. If it does not already exist, this
database can be created using the certutil utility. This process
and other certificate database maintenance information is provided in the
PCPIntro(1) manual page and the online PCP tutorials.
- -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.
- -M certname
- By default, pmproxy will try to use a certificate called PCP Collector
certificate in its server role. The -M option allows this to be
changed.
- -P passfile
- Specify the path to a file containing the Network Security Services
certificate database password for (optional) secure connections, and for
databases that are password protected. Refer also to the -C option.
When using this option, great care should be exercised to ensure
appropriate ownership ("pcp" user, typically) and permissions on
this file (0400, so as to be unreadable by any user other than the user
running the pmproxy process).
- -t,
--timeseries
- Operate in automatic archive timeseries discovery mode. This
(experimental) mode of operation will detect system archives created by
pmlogger(1) and import into a redis-server(1) automatically,
for fast, scalable timeseries queries.
- -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.
Normally, pmproxy is started automatically at boot time and
stopped when the system is being brought down. 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.iana.org/). Either
the environment variable PMPROXY_PORT -p command line option
may be used to specify alternative port number(s) when PMPROXY_PORT
or the -p command line option may be used to specify alternative port
number(s) when pmproxy is started; in each case, the specification is
a comma-separated list of one or more numerical port numbers. Should both
methods be used or multiple -p options appear on the command line,
pmproxy will listen on the union of the set of ports specified via
all -p options and the PMPROXY_PORT environment variable. If
non-default ports are used with pmproxy care should be taken to
ensure that PMPROXY_PORT is also set in the environment of any client
application that will connect to pmproxy, or that the extended host
specification syntax is used (see PCPIntro(1) for details).
- PCP_PMPROXYOPTIONS_PATH
- command line options for pmproxy when launched from
$PCP_RC_DIR/pmproxy All the command line option lines should start
with a hyphen as the first character.
- $PCP_SYSCONFIG_DIR/pmproxy
- additional environment variables that will be set when pmproxy
executes. Only settings of the form "PMPROXY_VARIABLE=value"
will be honoured.
- ./pmproxy.log
- (or $PCP_LOG_DIR/pmproxy/pmproxy.log when started automatically)
All messages and diagnostics are directed here
- /etc/pki/nssdb
- default Network Security Services (NSS) certificate database directory,
used for optional Secure Socket Layer connections. This database can be
created and queried using the NSS certutil tool, amongst
others.
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 superseded 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).
If set to the value 1, the PMPROXY_LOCAL environment
variable will cause pmproxy to run in a localhost-only mode of
operation, where it binds only to the loopback interface.
The PMPROXY_MAXPENDING variable can be set to indicate the
maximum length to which the queue of pending client connections may
grow.
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(5).
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 options, see
pmdbg(1), pmproxy currently supports the debugging option
context for tracing client connections and disconnections.