aannvviill [generic Postfix daemon options]
In the following text, iiddeenntt specifies a (service, client) combination. The exact syntax of that information is application-dependent; the aannvviill(8) server does not care.
To register a new connection send the following request to the aannvviill(8) server:
rreeqquueesstt==ccoonnnneecctt iiddeenntt==_s_t_r_i_n_g
The aannvviill(8) server answers with the number of simultaneous connections and the number of connections per unit time for the (service, client) combination specified with iiddeenntt:
ssttaattuuss==00 ccoouunntt==_n_u_m_b_e_r rraattee==_n_u_m_b_e_r
To register a disconnect event send the following request to the aannvviill(8) server:
rreeqquueesstt==ddiissccoonnnneecctt iiddeenntt==_s_t_r_i_n_g
The aannvviill(8) server replies with:
ssttaattuuss==00
To register a message delivery request send the following request to the aannvviill(8) server:
rreeqquueesstt==mmeessssaaggee iiddeenntt==_s_t_r_i_n_g
The aannvviill(8) server answers with the number of message delivery requests per unit time for the (service, client) combination specified with iiddeenntt:
ssttaattuuss==00 rraattee==_n_u_m_b_e_r
To register a recipient request send the following request to the aannvviill(8) server:
rreeqquueesstt==rreecciippiieenntt iiddeenntt==_s_t_r_i_n_g
The aannvviill(8) server answers with the number of recipient addresses per unit time for the (service, client) combination specified with iiddeenntt:
ssttaattuuss==00 rraattee==_n_u_m_b_e_r
The features described in this section are available with Postfix 2.3 and later.
To register a request for a new (i.e. not cached) TLS session send the following request to the aannvviill(8) server:
rreeqquueesstt==nneewwttllss iiddeenntt==_s_t_r_i_n_g
The aannvviill(8) server answers with the number of new TLS session requests per unit time for the (service, client) combination specified with iiddeenntt:
ssttaattuuss==00 rraattee==_n_u_m_b_e_r
To retrieve new TLS session request rate information without updating the counter information, send:
rreeqquueesstt==nneewwttllss__rreeppoorrtt iiddeenntt==_s_t_r_i_n_g
The aannvviill(8) server answers with the number of new TLS session requests per unit time for the (service, client) combination specified with iiddeenntt:
ssttaattuuss==00 rraattee==_n_u_m_b_e_r
The aannvviill(8) server does not talk to the network or to local users, and can run chrooted at fixed low privilege.
The aannvviill(8) server maintains an in-memory table with information about recent clients requests. No persistent state is kept because standard system library routines are not sufficiently robust for update-intensive applications.
Although the in-memory state is kept only temporarily, this may require a lot of memory on systems that handle connections from many remote clients. To reduce memory usage, reduce the time unit over which state is kept.
Upon exit, and every aannvviill__ssttaattuuss__uuppddaattee__ttiimmee seconds, the server logs the maximal count and rate values measured, together with (service, client) information and the time of day associated with those events. In order to avoid unnecessary overhead, no measurements are done for activity that isn't concurrency limited or rate limited.
In this preliminary implementation, a count (or rate) limited server process can have only one remote client at a time. If a server process reports multiple simultaneous clients, state is kept only for the last reported client.
The aannvviill(8) server automatically discards client request information after it expires. To prevent the aannvviill(8) server from discarding client request rate information too early or too late, a rate limited service should always register connect/disconnect events even when it does not explicitly limit them.
On low-traffic mail systems, changes to mmaaiinn..ccff are picked up automatically as aannvviill(8) processes run for only a limited amount of time. On other mail systems, use the command "ppoossttffiixx rreellooaadd" to speed up a change.
The text below provides only a parameter summary. See ppoossttccoonnff(5) for more details including examples.
smtpd(8), Postfix SMTP server postconf(5), configuration parameters master(5), generic daemon options
Use "ppoossttccoonnff rreeaaddmmee__ddiirreeccttoorryy" or "ppoossttccoonnff hhttmmll__ddiirreeccttoorryy" to locate this information.
TUNING_README, performance tuning
The Secure Mailer license must be distributed with this software.
The anvil service is available in Postfix 2.2 and later.
Wietse Venema IBM T.J. Watson Research P.O. Box 704 Yorktown Heights, NY 10598, USA