See also
gevent.setswitchinterval()
For additional runtime configuration.
Bases: object
Global configuration for gevent.
There is one instance of this object at gevent.config
. If you
are going to make changes in code, instead of using the documented
environment variables, you need to make the changes before using
any parts of gevent that might need those settings. For example:
>>> from gevent import config
>>> config.fileobject = 'thread'
>>> from gevent import fileobject
>>> fileobject.FileObject.__name__
'FileObjectThread'
New in version 1.3a2.
A list of strings giving the IP addresses of nameservers for the ares resolver.
In the environment variable, these strings are separated by commas.
Deprecated since version 1.3a2: Prefer the resolver_nameservers
setting. If both are set,
the results are not defined.
The default value is None
The environment variable GEVENTARES_SERVERS
can be used to control this.
Deprecated since version 1.3a2: Prefer the resolver_timeout
setting. If both are set,
the results are not defined.
The default value is None
The environment variable GEVENTARES_TIMEOUT
can be used to control this.
Should we not watch children with the event loop watchers?
This is an advanced setting.
See gevent.os
for a detailed description.
This is a boolean value.
In the environment variable, it may be given as 1
, true
,
on
or yes
for True
, or 0
, false
, off
, or
no
for False
.
The default value is False
The environment variable GEVENT_NOWAITPID
can be used to control this.
The kind of FileObject
we will use.
See gevent.fileobject
for a detailed description.
This is an importable value. It can be given as a string naming an importable object, or a list of strings in preference order and the first successfully importable object will be used. (Separate values in the environment variable with commas.) It can also be given as the callable object itself (in code). Shorthand names for default objects are [‘thread’, ‘posix’, ‘block’]
The default value is ['posix', 'thread']
The environment variable GEVENT_FILE
can be used to control this.
This is an importable value. It can be given as a string naming an importable object, or a list of strings in preference order and the first successfully importable object will be used. (Separate values in the environment variable with commas.) It can also be given as the callable object itself (in code).
The default value is pprint.saferepr
The environment variable GEVENT_FORMAT_CONTEXT
can be used to control this.
The backend for libev, such as ‘select’
The default value is None
The environment variable GEVENT_BACKEND
can be used to control this.
The kind of the loop we use.
On Windows, this defaults to libuv, while on other platforms it defaults to libev.
This is an importable value. It can be given as a string naming an importable object, or a list of strings in preference order and the first successfully importable object will be used. (Separate values in the environment variable with commas.) It can also be given as the callable object itself (in code). Shorthand names for default objects are [‘libev-cext’, ‘libev-cffi’, ‘libuv-cffi’, ‘libuv’]
The default value is ['libev-cext', 'libev-cffi', 'libuv-cffi']
The environment variable GEVENT_LOOP
can be used to control this.
If the monitor_thread
is enabled, this is
approximately how long (in seconds)
the event loop will be allowed to block before a warning is issued.
This function depends on using greenlet.settrace
, so installing
your own trace function after starting the monitoring thread will
cause this feature to misbehave unless you call the function
returned by greenlet.settrace
. If you install a tracing function before
the monitoring thread is started, it will still be called.
Note
In the unlikely event of creating and using multiple different gevent hubs in the same native thread in a short period of time, especially without destroying the hubs, false positives may be reported.
New in version 1.3b1.
The default value is 0.1
The environment variable GEVENT_MAX_BLOCKING_TIME
can be used to control this.
If monitor_thread
is enabled,
then if memory usage exceeds this amount (in bytes), events will
be emitted. See gevent.events
. In the environment variable, you can use
a suffix of ‘kb’, ‘mb’ or ‘gb’ to specify the value in kilobytes, megabytes
or gigibytes.
There is no default value for this setting. If you wish to cap memory usage, you must choose a value.
The default value is None
The environment variable GEVENT_MONITOR_MEMORY_MAX
can be used to control this.
If monitor_thread
is enabled, this is approximately how long
(in seconds) we will go between checking the processes memory usage.
Checking the memory usage is relatively expensive on some operating systems, so this should not be too low. gevent will place a floor value on it.
The default value is 5
The environment variable GEVENT_MONITOR_MEMORY_PERIOD
can be used to control this.
Should each hub start a native OS thread to monitor for problems?
Such a thread will periodically check to see if the event loop
is blocked for longer than max_blocking_time
, producing output on
the hub’s exception stream (stderr by default) if it detects this condition.
If this setting is true, then this thread will be created
the first time the hub is switched to,
or you can call gevent.hub.Hub.start_periodic_monitoring_thread()
at any
time to create it (from the same thread that will run the hub). That function
will return an instance of gevent.events.IPeriodicMonitorThread
to which you can add your own monitoring functions. That function
also emits an event of gevent.events.PeriodicMonitorThreadStartedEvent
.
See also
New in version 1.3b1.
This is a boolean value.
In the environment variable, it may be given as 1
, true
,
on
or yes
for True
, or 0
, false
, off
, or
no
for False
.
The default value is False
The environment variable GEVENT_MONITOR_THREAD_ENABLE
can be used to control this.
The callable that will be used to create
gevent.hub.Hub.resolver
.
See Name Resolution (DNS) for more information.
This is an importable value. It can be given as a string naming an importable object, or a list of strings in preference order and the first successfully importable object will be used. (Separate values in the environment variable with commas.) It can also be given as the callable object itself (in code). Shorthand names for default objects are [‘ares’, ‘thread’, ‘block’, ‘dnspython’]
The default value is ['thread', 'dnspython', 'ares', 'block']
The environment variable GEVENT_RESOLVER
can be used to control this.
A list of strings giving the IP addresses of nameservers for the (non-system) resolver.
In the environment variable, these strings are separated by commas.
Resolver Behaviour
blocking
Ignored
Threaded
Ignored
dnspython
If this setting is not given, the dnspython resolver will
load nameservers to use from /etc/resolv.conf
or the Windows registry. This setting replaces any nameservers read
from those means. Note that the file and registry are still read
for other settings.
Caution
dnspython does not validate the members of the list. An improper address (such as a hostname instead of IP) has undefined results, including hanging the process.
ares
Similar to dnspython, but with more platform and compile-time options. ares validates that the members of the list are valid addresses.
The default value is None
The environment variable GEVENT_RESOLVER_NAMESERVERS
can be used to control this.
The total amount of time that the DNS resolver will spend making queries.
Only the ares and dnspython resolvers support this.
New in version 1.3a2.
The default value is None
The environment variable GEVENT_RESOLVER_TIMEOUT
can be used to control this.
The kind of threadpool we use.
This is an importable value. It can be given as a string naming an importable object, or a list of strings in preference order and the first successfully importable object will be used. (Separate values in the environment variable with commas.) It can also be given as the callable object itself (in code).
The default value is gevent.threadpool.ThreadPool
The environment variable GEVENT_THREADPOOL
can be used to control this.
How long threads in the default threadpool (used for DNS by default) are allowed to be idle before exiting.
Use -1 for no timeout.
New in version 22.08.0.
The default value is 5.0
The environment variable GEVENT_THREADPOOL_IDLE_TASK_TIMEOUT
can be used to control this.
Should FFI objects track their allocation?
This is only useful for low-level debugging.
On Python 3, this environment variable is built in to the
interpreter, and it may also be set with the -X
tracemalloc
command line argument.
On Python 2, gevent interprets this argument and adds extra tracking information for FFI objects.
The default value is False
The environment variable PYTHONTRACEMALLOC
can be used to control this.
Should Greenlet
objects track their spawning tree?
Setting this to a false value will make spawning Greenlet
objects and using spawn_raw
faster, but the
spawning_greenlet
, spawn_tree_locals
and spawning_stack
will not be captured. Setting this to a false value can also
reduce memory usage because capturing the stack captures
some information about Python frames.
New in version 1.3b1.
This is a boolean value.
In the environment variable, it may be given as 1
, true
,
on
or yes
for True
, or 0
, false
, off
, or
no
for False
.
The default value is True
The environment variable GEVENT_TRACK_GREENLET_TREE
can be used to control this.
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