This chapter describes the snmp
application in OTP. The SNMP application provides the following
services:
-
a multilingual extensible SNMP agent
-
a SNMP manager
-
a MIB compiler
The following configuration parameters are defined for the SNMP
application. Refer to application(3) for more information about
configuration parameters.
The snmp part of the config file specifying the configuration
parameters is basically the following tuple:
{snmp, snmp_components_config()}
A minimal config file for starting a node with both a manager
and an agent:
[{snmp,
[{agent, [{db_dir, "/tmp/snmp/agent/db"},
{config, [{dir, "/tmp/snmp/agent/conf"}]}]},
{manager, [{config, [{dir, "/tmp/snmp/manager/conf"},
{db_dir, "/tmp/snmp/manager/db"}]}]}]}
]
}
].
Each snmp component has it's own set of configuration parameters,
even though some of the types are common to both components.
snmp_components_config() -> [snmp_component_config()]
snmp_component_config() -> {agent, agent_options()} | {manager, manager_options()}
agent_options() = [agent_option()]
agent_option() = {restart_type, restart_type()} |
{agent_type, agent_type()} |
{agent_verbosity, verbosity()} |
{versions, versions()} |
{priority, priority()} |
{multi_threaded, multi_threaded()} |
{db_dir, db_dir()} |
{db_init_error, db_init_error()} |
{local_db, local_db()} |
{net_if, agent_net_if()} |
{mibs, mibs()} |
{mib_storage, mib_storage()} |
{mib_server, mib_server()} |
{audit_trail_log, audit_trail_log()} |
{error_report_mod, error_report_mod()} |
{note_store, note_store()} |
{symbolic_store, symbolic_store()} |
{target_cache, target_cache()} |
{config, agent_config()}
manager_options() = [manager_option()]
manager_option() = {restart_type, restart_type()} |
{net_if, manager_net_if()} |
{server, server()} |
{note_store, note_store()} |
{config, manager_config()} |
{inform_request_behaviour, manager_irb()} |
{mibs, manager_mibs()} |
{priority, priority()} |
{audit_trail_log, audit_trail_log()} |
{versions, versions()} |
{def_user_mod, def_user_module() |
{def_user_data, def_user_data()}
Agent specific config options and types:
-
agent_type() = master | sub <optional>
-
If master, one master agent is
started. Otherwise, no agents are started.
Default is master.
-
multi_threaded() = bool() <optional>
-
If true, the agent is multi-threaded, with one
thread for each get request.
Default is false.
-
db_dir() = string() <mandatory>
-
Defines where the SNMP agent internal db files are stored.
-
local_db() = [local_db_opt()] <optional>
-
local_db_opt() = {repair, agent_repair()} | {auto_save, agent_auto_save()} | {verbosity, verbosity()}
Defines options specific for the SNMP agent local database.
For defaults see the options in local_db_opt().
-
agent_repair() = false | true | force <optional>
-
When starting snmpa_local_db it always tries to open an
existing database. If false, and some errors occur, a new
database is created instead. If true, an existing file
will be repaired. If force, the table will be repaired
even if it was properly closed.
Default is true.
-
agent_auto_save() = integer() | infinity <optional>
-
The auto save interval. The table is flushed to disk
whenever not accessed for this amount of time.
Default is 5000.
-
agent_net_if() = [agent_net_if_opt()] <optional>
-
agent_net_if_opt() = {module, agent_net_if_module()} | {verbosity, verbosity()} | {options, agent_net_if_options()}
Defines options specific for the SNMP agent network interface
entity.
For defaults see the options in agent_net_if_opt().
-
agent_net_if_module() = atom() <optional>
-
Module which handles the network interface part for the
SNMP agent. Must implement the
snmpa_network_interface behaviour.
Default is snmpa_net_if.
-
agent_net_if_options() = [agent_net_if_option()] <optional>
-
agent_net_if_option() = {bind_to, bind_to()} |
{sndbuf, sndbuf()} |
{recbuf, recbuf()} |
{no_reuse, no_reuse()} |
{req_limit, req_limit()} |
{filter, agent_net_if_filter_options()}
These options are actually specific to the used module.
The ones shown here are applicable to the default
agent_net_if_module().
For defaults see the options in agent_net_if_option().
-
req_limit() = integer() | infinity <optional>
-
Max number of simultaneous requests handled by the agent.
Default is infinity.
-
agent_net_if_filter_options() = [agent_net_if_filter_option()] <optional>
-
agent_net_if_filter_option() = {module, agent_net_if_filter_module()}
These options are actually specific to the used module.
The ones shown here are applicable to the default
agent_net_if_filter_module().
For defaults see the options in
agent_net_if_filter_option().
-
agent_net_if_filter_module() = atom() <optional>
-
Module which handles the network interface filter part for the
SNMP agent. Must implement the
snmpa_network_interface_filter behaviour.
Default is snmpa_net_if_filter.
-
agent_mibs() = [string()] <optional>
-
Specifies a list of MIBs (including path) that defines which MIBs
are initially loaded into the SNMP master agent.
Note that the following mibs will always be loaded:
-
version v1: STANDARD-MIB
-
version v2: SNMPv2
-
version v3: SNMPv2, SNMP-FRAMEWORK-MIB
and SNMP-MPD-MIB
Default is [].
-
mib_storage() = ets | {ets, Dir} | {ets, Dir, Action} | dets | {dets, Dir} | {dets, Dir, Action} | mnesia | {mnesia, Nodes} | {mnesia, Nodes, Action} <optional>
-
Specifies how info retrieved from the mibs will be stored.
If mib_storage is {ets, Dir}, the table will also be
stored on file. If Dir is default, then db_dir
will be used.
If mib_storage is dets or if Dir is
default, then db_dir will be used for Dir.
If mib_storage is mnesia then erlang:nodes()
will be used for Nodes.
Default is ets.
Dir = default | string(). Dir is the directory where the
files will be stored. If default, then db_dir will be
used.
Nodes = visible | connected | [node()].
Nodes = visible is translated to
erlang:nodes(visible).
Nodes = connected is translated to
erlang:nodes(connected).
If Nodes = [] then the own node is assumed.
Action = clear | keep. Default is keep.
Action is used to specify what shall be done if the
mnesia/dets table already exist.
-
mib_server() = [mib_server_opt()] <optional>
-
mib_server_opt() = {mibentry_override, mibentry_override()} | {trapentry_override, trapentry_override()} | {verbosity, verbosity()} | {cache, mibs_cache()}
Defines options specific for the SNMP agent mib server.
For defaults see the options in mib_server_opt().
-
mibentry_override() = bool() <optional>
-
If this value is false, then when loading a mib each mib-
entry is checked prior to installation of the mib.
The purpose of the check is to prevent that the same symbolic
mibentry name is used for different oid's.
Default is false.
-
trapentry_override() = bool() <optional>
-
If this value is false, then when loading a mib each trap
is checked prior to installation of the mib.
The purpose of the check is to prevent that the same symbolic
trap name is used for different trap's.
Default is false.
-
mibs_cache() = bool() <optional>
-
Shall the agent utilize the mib server lookup cache or not.
Default is true.
-
error_report_mod() = atom() <optional>
-
Defines an error report module, implementing the
snmpa_error_report
behaviour. Two modules are provided with the toolkit:
snmpa_error_logger and snmpa_error_io.
Default is snmpa_error_logger.
-
symbolic_store() = [symbolic_store_opt()]
-
symbolic_store_opt() = {verbosity, verbosity()}
Defines options specific for the SNMP agent symbolic store.
For defaults see the options in symbolic_store_opt().
-
target_cache() = [target_cache_opt()]
-
target_cache_opt() = {verbosity, verbosity()}
Defines options specific for the SNMP agent target cache.
For defaults see the options in target_cache_opt().
-
agent_config() = [agent_config_opt()] <mandatory>
-
agent_config_opt() = {dir, agent_config_dir()} | {force_load, force_load()} | {verbosity, verbosity()}
Defines specific config related options for the SNMP agent.
For defaults see the options in agent_config_opt().
-
agent_config_dir = dir() <mandatory>
-
Defines where the SNMP agent configuration files are stored.
-
force_load() = bool() <optional>
-
If true the configuration files are re-read
during start-up, and the contents of the configuration
database ignored. Thus, if true, changes to
the configuration database are lost upon reboot of the
agent.
Default is false.
Manager specific config options and types:
-
server() = [server_opt()] <optional>
-
server_opt() = {timeout, server_timeout()} | {verbosity, verbosity()}
Specifies the options for the manager server process.
Default is silence.
-
server_timeout() = integer() <optional>
-
Asynchroneous request cleanup time. For every requests,
some info is stored internally, in order to be able to
deliver the reply (when it arrives) to the proper destination.
If the reply arrives, this info will be deleted. But if
there is no reply (in time), the info has to be deleted
after the best before time has been passed.
This cleanup will be performed at regular intervals, defined
by the server_timeout() time.
The information will have an best before time,
defined by the Expire time given when calling the
request function (see
async_get,
async_get_next and
async_set).
Time in milli-seconds.
Default is 30000.
-
manager_config() = [manager_config_opt()] <mandatory>
-
manager_config_opt() = {dir, manager_config_dir()} | {db_dir, manager_db_dir()} | {db_init_error, db_init_error()} | {repair, manager_repair()} | {auto_save, manager_auto_save()} | {verbosity, verbosity()}
Defines specific config related options for the SNMP manager.
For defaults see the options in manager_config_opt().
-
manager_config_dir = dir() <mandatory>
-
Defines where the SNMP manager configuration files are stored.
-
manager_db_dir = dir() <mandatory>
-
Defines where the SNMP manager store persistent data.
-
manager_repair() = false | true | force <optional>
-
Defines the repair option for the persistent database (if
and how the table is repaired when opened).
Default is true.
-
manager_auto_save() = integer() | infinity <optional>
-
The auto save interval. The table is flushed to disk
whenever not accessed for this amount of time.
Default is 5000.
-
manager_irb() = auto | user | {user, integer()} <optional>
-
This option defines how the manager will handle the sending of
response (acknowledgment) to received inform-requests.
-
auto - The manager will autonomously send response
(acknowledgment> to inform-request messages.
-
{user, integer()} - The manager will send response
(acknowledgment) to inform-request messages when the
handle_inform
function completes. The integer is the time, in milli-seconds,
that the manager will consider the stored inform-request info
valid.
-
user - Same as {user, integer()}, except that
the default time, 15 seconds (15000), is used.
See
snmpm_network_interface,
handle_inform and
definition of the manager net if for more info.
Default is auto.
-
manager_mibs() = [string()] <optional>
-
Specifies a list of MIBs (including path) and defines which MIBs
are initially loaded into the SNMP manager.
Default is [].
-
manager_net_if() = [manager_net_if_opt()] <optional>
-
manager_net_if_opt() = {module, manager_net_if_module()} | {verbosity, verbosity()} | {options, manager_net_if_options()}
Defines options specific for the SNMP manager network interface
entity.
For defaults see the options in manager_net_if_opt().
-
manager_net_if_options() = [manager_net_if_option()] <optional>
-
manager_net_if_option() = {bind_to, bind_to()} | {sndbuf, sndbuf()} | {recbuf, recbuf()} | {no_reuse, no_reuse()}
These options are actually specific to the used module.
The ones shown here are applicable to the default
manager_net_if_module().
For defaults see the options in manager_net_if_option().
-
manager_net_if_module() = atom() <optional>
-
Module which handles the network interface part for the
SNMP manager. Must implement the
snmpm_network_interface behaviour.
Default is snmpm_net_if.
-
def_user_module() = atom() <optional>
-
The module implementing the default user. See the
snmpm_user behaviour.
Default is snmpm_user_default.
-
def_user_data() = term() <optional>
-
Data for the default user. Passed to the user module when
calling the callback functions.
Default is undefined.
Common config types:
-
restart_type() = permanent | transient | temporary
-
See supervisor
documentation for more info.
Default is permanent for the agent and transient
for the manager.
-
db_init_error() = terminate | create
-
Defines what to do if the agent or manager is unable to open an
existing database file. terminate means that the
agent/manager will terminate and create means that the
agent/manager will remove the faulty file(s) and create new ones.
Default is terminate.
-
priority() = atom() <optional>
-
Defines the Erlang priority for all SNMP processes.
Default is normal.
-
versions() = [version()] <optional>
-
version() = v1 | v2 | v3
Which SNMP versions shall be accepted/used.
Default is [v1,v2,v3].
-
verbosity() = silence | info | log | debug | trace <optional>
-
Verbosity for a SNMP process. This specifies now much debug info
is printed.
Default is silence.
-
bind_to() = bool() <optional>
-
If true, net_if binds to the IP address.
If false, net_if listens on any IP address on the host
where it is running.
Default is false.
-
no_reuse() = bool() <optional>
-
If true, net_if does not specify that the IP
and port address should be reusable. If false,
the address is set to reusable.
Default is false.
-
recbuf() = integer() <optional>
-
Receive buffer size.
Default value is defined by gen_udp.
-
sndbuf() = integer() <optional>
-
Send buffer size.
Default value is defined by gen_udp.
-
note_store() = [note_store_opt()] <optional>
-
note_store_opt() = {timeout, note_store_timeout()} | {verbosity, verbosity()}
Specifies the start-up verbosity for the SNMP note store.
For defaults see the options in note_store_opt().
-
note_store_timeout() = integer() <optional>
-
Note cleanup time. When storing a note in the note store,
each note is given lifetime. Every timeout the note_store
process performs a GC to remove the expired note's. Time in
milli-seconds.
Default is 30000.
-
audit_trail_log() = [audit_trail_log_opt()] <optional>
-
audit_trail_log_opt() = {type, atl_type()} | {dir, atl_dir()} | {size, atl_size()} | {repair, atl_repair()}
If present, this option specifies the options for the
audit trail logging. The disk_log module is used
to maintain a wrap log. If present, the dir and
size options are mandatory.
If not present, audit trail logging is not used.
-
atl_type() = read | write | read_write <optional>
-
Specifies what type of an audit trail log should be used.
The effect of the type is actually different for the the agent
and the manager.
For the agent:
-
If write is specified, only set requests are logged.
-
If read is specified, only get requests are logged.
-
If read_write, all requests are logged.
For the manager:
-
If write is specified, only sent messages are logged.
-
If read is specified, only received messages are logged.
-
If read_write, both outgoing and incoming messages are
logged.
Default is read_write.
-
atl_dir = dir() <mandatory>
-
Specifies where the audit trail log should be stored.
If audit_trail_log specifies that logging should take
place, this parameter must be defined.
-
atl_size() = {integer(), integer()} <mandatory>
-
Specifies the size of the audit
trail log. This parameter is sent to disk_log.
If audit_trail_log specifies that logging should
take place, this parameter must be defined.
-
atl_repair() = true | false | truncate | snmp_repair <optional>
-
Specifies if and how the audit trail log shall be repaired
when opened. Unless this parameter has the value snmp_repair
it is sent to disk_log. If, on the other hand, the value is
snmp_repair, snmp attempts to handle certain faults on it's
own. And even if it cannot repair the file, it does not truncate it
directly, but instead moves it aside for later off-line
analysis.
Default is true.
application(3), disk_log(3)