# pmproxy

## NAME



           **pmproxy** - proxy for performance metrics collector and querying
    


## SYNOPSIS



           **pmproxy**[**-AdfFt?**]  [**-c** _conffile_] [**-D** _debug_] [**-h** _host_[,_host_ ...]
           [**-i** _ipaddress_] [**-l** _logfile_] [**-L** _bytes_] [**-p** _port_[,_port_ ...]  [**-r**
           _port_[,_port_ ...]  [**-s** _sockname_] [**-U** _username_] [**-x** _outfile_]
    


## DESCRIPTION



           **pmproxy** acts as a protocol proxy, allowing Performance Co-Pilot
           (PCP) monitoring clients to connect to one or more pmcd(1) and/or
           key-value servers (such as **https://valkey.io/ **) indirectly.
    
           In its default mode of operation **pmproxy** provides the REST API for
           PCP services (see PMWEBAPI(3) for details).  This includes
           provision of an Open Metrics - _https://openmetrics.io _ - text
           interface for PCP metrics at _/metrics_ , real-time access to PCP
           metrics through the _/pmapi_ interfaces, and access to the fast,
           scalable PCP time series query capabilities offered in conjunction
           with a key-value server (see pmseries(1) for details) via the
           _/query_ REST interfaces.
    
           **pmproxy** can be deployed in a firewall domain, or on a cluster
           ``head'' node where the IP (Internet Protocol) address of the
           hosts where **pmcd** and/or a key-value server (such as
           **https://valkey.io/ **) are running may be unknown to the PCP
           monitoring clients, but where the IP address of the host running
           **pmproxy** 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** and/or a key-value server are
           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
           PMAPI(3) connections directly to **pmcd**.  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** or a key-value server indirectly
           through the protocol proxy services of **pmproxy.**
    


## OPTIONS



           The available command line options are:
    
           **-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** _conffile_ , **--config** =_conffile_
                Specify the path to an optional configuration _conffile_ , with
                format as described in the ``CONFIGURATION'' section.  This
                option implies **pmproxy** is running in **timeseries** mode.
    
           **-d** , **--deprecated**
                By default **pmproxy** prefers to run in the new **timeseries** mode,
                providing REST APIs, asynchronous network I/O, scalable time
                series, and secure connections using OpenSSL.  However,
                legacy deployments may wish to use the original synchronous
                **pmproxy** implementation using libpcp networking; this can be
                achieved using this option.  Note that the **-d** and **-t** options
                are mutually exclusive.
    
           **-f** , **--foreground**
                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.
    
           **-F** , **--systemd**
                Like **-f** , the **-F** option runs **pmproxy** in the foreground, but
                also does some housekeeping (like create a ``pid'' file and
                change user id).  This is intended for use when **pmproxy** is
                launched from systemd(1) and the daemonising has already been
                done by systemd(1) and does not need to be done again by
                **pmproxy** , which is the case when neither **-f** nor **-F** is
                specified.
    
                At most one of **-f** and **-F** may be specified.
    
           **-h** _host_ , **--keyhost** =_host_
                Specify an alternate key-value server _host_ to connect to for
                time series querying, overriding any configuration file
                settings.  This option implies **pmproxy** is running in
                **timeseries** mode.
    
           **-i** _ipaddress_ , **--interface** =_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 likely to be deployed to arbitrate
                access to an internal network).  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_ , **--log** =_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 a given _logfile_ instead of the default.  If this
                _logfile_ cannot be created or is not writable, output is
                written to the standard error instead.
    
           **-L** _bytes_
                _PDU_ s 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.
    
           **-p** _port_ , **--port** =_port_
                Specify an alternate _port_ number to listen on for client
                connections.  The default value is 44322.
    
           **-r** _port_ , **--keyport** =_port_
                Specify an alternate key-value server _port_ number to connect
                to for time series querying, overriding any configuration
                file settings.  This option implies **pmproxy** is running in
                **timeseries** mode.
    
           **-s** _sockname_ , **--socket** =_sockname_
                Specify the path to a local unix domain socket (for platforms
                supporting this socket family only).  The default value is
                _$PCP_RUN_DIR/pmproxy.socket_.  This option implies **pmproxy** is
                running in **timeseries** mode.
    
           **-t** , **--timeseries**
                Operate in automatic archive timeseries discovery mode.  This
                mode of operation will enable the PMWEBAPI(3) REST APIs,
                dynamically and automatically detect active system archives
                being written by pmlogger(1) and import them into a key-value
                server (such as **https://valkey.io/ **), for fast, scalable time
                series querying described in pmseries(1).  Note that in this
                mode of operation, **pmproxy** only "log-tails" and ingests
                actively growing archives, e.g. as written by one or more
                pmlogger(1) instances.  When an archive is first discovered
                (usually but not limited to **pmproxy** startup), all metadata is
                loaded and sent to the configured key-value server however
                note that only **new** archive metric value data from the tail
                end of each archive is ingested.  Compressed archives never
                grow and so are ignored.  See the **--load** option to
                pmseries(1) for a supported mechanism for manually loading
                all of the metric value data from previously collected
                (inactive) archives, whether compressed or not.  It would be
                normal, though not mandated, for a set of archives being
                manually loaded to cover the same time period, e.g. archive
                data for a particular week for one or more hosts in the same
                data-centre.
    
           **-U** _username_ , **--username** =_username_
                Assume the identity of the given _username_ before starting to
                accept incoming packets from PCP monitoring clients.
    
           **-x** _outfile_
                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 _outfile_.
    
           **-?** , **--help**
                Display usage message and exit.
    


## CONFIGURATION



           When running in the **timeseries** mode of operation, runtime
           configuration is relatively complex and typically handled via the
           _$PCP_SYSCONF_DIR/pmproxy/pmproxy.conf_ file.  This file is in the
           common ``ini'' format, with section headers and individual
           variables and values with each section.  The configuration file
           installed as part of PCP documents every available section and
           option.
    
           At a high level, the _[pmproxy]_ section can be used to explicitly
           enable or disable each of the different protocols.
    
           The _[http]_ section provides fine-tuning over HTTP server settings
           used by **pmproxy.**_chunksize_ sets the chunked transfer encoding
           buffer size, and defaults to the system pagesize.  Access control
           HTTP protocol settings can be adjusted using the _Access-Control-_
           _Allow-Headers_ and _Access-Control-Max-Age_ options.  Discussion of
           these HTTP protocol headers is beyond the scope of this document,
           but suitable default values are described within the _pmproxy.conf_
           configuration file.
    
           The _[keys]_ section allows connection information for one or more
           backing key-value server processes to be configured (hostnames and
           ports).  Note to access multiple (scalable) key-value servers, the
           _servers_ variable in this section can be a comma-separated list of
           hostname:port pairs.  Alternatively, it can be a single key-value
           server host that will be queried using the "CLUSTER INFO" command
           to automatically configure multiple backing hosts.
    
           In earlier versions of PCP (before 6) an alternative configuration
           setting section was used for this purpose - key-value _servers_ were
           specified in the _[pmseries]_ section and this is still accepted as
           a fallback for backwards compatibility.
    


## STARTING AND STOPPING PMPROXY



           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 (as well as 44323 with **timeseries** enabled) registered
           at **https://www.iana.org/ **.  Either the environment variable
           **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).
    


## 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 options, see pmdbg(1),
           **pmproxy** currently supports the debugging option **context** for
           tracing client connections and disconnections.
    


## FILES



           _$PCP_PMPROXYOPTIONS_PATH_
                command line options for **pmproxy** when launched from
                **$PCP_RC_DIR/pmproxy** All the command line option lines should
                start with a hyphen as the first character.
    
           _$PCP_SYSCONFIG_DIR/pmproxy_
                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/tls_
                default OpenSSL certificate database directory, optionally
                used for Secure Socket Layer connection in **timeseries** mode of
                operation.  These certificates can be created and queried
                using the **openssl** tool, amongst others.
    


## 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,
           **pmproxy** and **pmcd**.
    
           **PMCD_PORT**
                  For the PCP monitoring client this (or the default port
                  number) is passed to **pmproxy** and used to connect to **pmcd**.
                  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, as
                  well as 44323 with **timeseries** enabled.
    
           **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** 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.
    


## 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(5).
    
           For environment variables affecting PCP tools, see
           pmGetOptions(3).
    


## DEBUGGING OPTIONS



           The **-D** or **--debug** option enables the output of additional
           diagnostics on _stderr_ to help triage problems, although the
           information is sometimes cryptic and primarily intended to provide
           guidance for developers rather end-users.  _debug_ is a comma
           separated list of debugging options; use pmdbg(1) with the **-l**
           option to obtain a list of the available debugging options and
           their meaning.
    
           Debugging options specific to **pmproxy** are as follows:
           ┌────────┬───────────────────────────────────────────────────────┐
           │ **Option** │ **Description** │
           ├────────┼───────────────────────────────────────────────────────┤
           │ **appl0** │ client connections and disconnections                 │
           ├────────┼───────────────────────────────────────────────────────┤
           │ **appl1** │ desperate logging mode, where a period followed by    │
           │        │ the PID of **pmproxy** is inserted in the name of _logfile_ │
           │        │ before the last period, so for example pmproxy.log    │
           │        │ becomes pmproxy.<pid>.log                             │
           ├────────┼───────────────────────────────────────────────────────┤
           │ **appl2** │ log incoming HTTP URLs (this is also enabled by the   │
           │        │ **http** debugging option, but the latter has broader     │
           │        │ scope because it turns on debugging in the libraries  │
           │        │ that **pmproxy** uses)                                    │
           └────────┴───────────────────────────────────────────────────────┘
    


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