From 3d70cee4034e4da37d125679345aa2a10c58cb34 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Tue, 14 Apr 2015 23:21:36 +0200 Subject: Update Kernel documentation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Language cleaned up by technical writers from Combitech. Proofreading and corrections by Björn Gustavsson and Hans Bolinder. --- lib/kernel/doc/src/kernel_app.xml | 342 ++++++++++++++++++-------------------- 1 file changed, 165 insertions(+), 177 deletions(-) (limited to 'lib/kernel/doc/src/kernel_app.xml') diff --git a/lib/kernel/doc/src/kernel_app.xml b/lib/kernel/doc/src/kernel_app.xml index 956c57f7c1..9e6fb60bb7 100644 --- a/lib/kernel/doc/src/kernel_app.xml +++ b/lib/kernel/doc/src/kernel_app.xml @@ -4,7 +4,7 @@
- 19962015 + 19962016 Ericsson AB. All Rights Reserved. @@ -29,66 +29,59 @@
kernel - The Kernel Application + The Kernel application. -

The Kernel application is the first application started. It is +

The Kernel application has all the code necessary to run + the Erlang runtime system: file servers, code servers, + and so on.

+

The Kernel application is the first application started. It is mandatory in the sense that the minimal system based on - Erlang/OTP consists of Kernel and STDLIB. The Kernel application - contains the following services:

+ Erlang/OTP consists of Kernel and STDLIB. Kernel + contains the following functional areas:

- application controller, see application(3) - code - disk_log - dist_ac, distributed application controller - erl_boot_server - erl_ddll - error_logger - error_logger_format_depth - file - global - global_group - heart - inet - net_kernel - os - pg2 - rpc - seq_trace - user + Start, stop, supervision, configuration, and distribution of applications + Code loading + Logging + Error logging + Global name service + Supervision of Erlang/OTP + Communication with sockets + Operating system interface
Error Logger Event Handlers

Two standard error logger event handlers are defined in - the Kernel application. These are described in - error_logger(3).

+ the Kernel application. These are described in + error_logger(3).

Configuration -

The following configuration parameters are defined for the Kernel - application. See app(4) for more - information about configuration parameters.

+

The following configuration parameters are defined for the Kernel + application. For more information about configuration parameters, + see file app(4).

browser_cmd = string() | {M,F,A} -

When pressing the Help button in a tool such as Debugger or - TV, the help text (an HTML file File) is by default - displayed in a Netscape browser which is required to be up and - running. This parameter can be used to change the command for +

When pressing the Help button in a tool such as Debugger, + the help text (an HTML file File) is by default + displayed in a Netscape browser, which is required to be + operational. This parameter can be used to change the command for how to display the help text if another browser than Netscape - is preferred, or another platform than Unix or Windows is + is preferred, or if another platform than Unix or Windows is used.

If set to a string Command, the command - "Command File" will be evaluated using os:cmd/1.

-

If set to a module-function-args tuple {M,F,A}, - the call apply(M,F,[File|A]) will be evaluated.

+ "Command File" is evaluated using + os:cmd/1.

+

If set to a module-function-args tuple, {M,F,A}, + the call apply(M,F,[File|A]) is evaluated.

 distributed = [Distrib] -

Specifies which applications are distributed and on which - nodes they may execute. In this parameter:

+

Specifies which applications that are distributed and on which + nodes they are allowed to execute. In this parameter:

Distrib = {App,Nodes} | {App,Time,Nodes} App = atom() @@ -96,25 +89,24 @@ Nodes = [node() | {node(),...,node()}]

The parameter is described in - application(3), function - load/2.

+ application:load/2.

 dist_auto_connect = Value -

Specifies when nodes will be automatically connected. If +

Specifies when nodes are automatically connected. If this parameter is not specified, a node is always - automatically connected, e.g when a message is to be sent to + automatically connected, for example, when a message is to be sent to that node. Value is one of:

never - Connections are never automatically established, they +

Connections are never automatically established, they must be explicitly connected. See - net_kernel(3). + net_kernel(3).

 once - Connections will be established automatically, but only +

Connections are established automatically, but only once per node. If a node goes down, it must thereafter be explicitly connected. See - net_kernel(3). + net_kernel(3).

 permissions = [Perm] @@ -127,25 +119,24 @@ Bool = boolean()

Permissions are described in - application(3), function - permit/2.

+ application:permit/2.

error_logger = Value

Value is one of:

tty - Installs the standard event handler which prints error - reports to stdio. This is the default option. +

Installs the standard event handler, which prints error + reports to stdio. This is the default option.

 {file, FileName} - Installs the standard event handler which prints error - reports to the file FileName, where FileName - is a string. +

Installs the standard event handler, which prints error + reports to file FileName, where FileName + is a string.

 false

No standard event handler is installed, but the initial, primitive event handler is kept, printing - raw event messages to tty.

+ raw event messages to tty.

 silent @@ -156,111 +147,110 @@ error_logger_format_depth = Depth -

This parameter can be used to limit the size of the +

Can be used to limit the size of the formatted output from the error logger event handlers.

-

This configuration parameter was introduced in OTP 18.1. - It is currently experimental. Based on user feedback it - may be changed or improved in future releases, for example +

This configuration parameter was introduced in OTP 18.1 + and is experimental. Based on user feedback, it + can be changed or improved in future releases, for example, to gain better control over how to limit the size of the - formatted output. We have no plans to entirely remove this - new feature, unless it turns out to be completely - useless. In OTP 19, the default may be changed to limit the - formatted output.

 + formatted output. We have no plans to remove this + new feature entirely, unless it turns out to be + useless.

-

Depth is a positive integer that is the maximum +

Depth is a positive integer representing the maximum depth to which terms are printed by the error logger event - handlers included in OTP. Specifically, the two event handlers + handlers included in OTP. This + configuration parameter is used by the two event handlers defined by the Kernel application and the two event - handlers in the SASL application will use this - configuration parameter. (If you have implemented you own - error handlers, this configuration parameter will have no - effect on them.)

+ handlers in the SASL application. + (If you have implemented your own error handlers, this configuration + parameter has no effect on them.)

-

The way Depth is used, is that format strings - string passed to the event handlers will be rewritten. - The "~p" and "~w" format controls will be replaced with - "~P" and "~W", respectively, and Depth will be - used as the depth parameter. See - io:format/2.

+

Depth is used as follows: Format strings + passed to the event handlers are rewritten. + The format controls ~p and ~w are replaced with + ~P and ~W, respectively, and Depth is + used as the depth parameter. For details, see + io:format/2 + in STDLIB.

A reasonable starting value for Depth is - 30. You should test crashing various processes in your - application and examine the logs from the crashes, and then - either increase or decrease the value.

 + 30. We recommend to test crashing various processes in your + application, examine the logs from the crashes, and then + increase or decrease the value.

 global_groups = [GroupTuple] +

Defines global groups, see - global_group(3).

+ global_group(3). + In this parameter:

- GroupTuple = {GroupName, [Node]} | {GroupName, PublishType, [Node]} - GroupName = atom() - PublishType = normal | hidden - Node = node() +

GroupTuple = {GroupName, [Node]} | {GroupName, PublishType, [Node]}

 +

GroupName = atom()

 +

PublishType = normal | hidden

 +

Node = node()

 inet_default_connect_options = [{Opt, Val}]

Specifies default options for connect sockets, - see inet(3).

+ see inet(3).

 inet_default_listen_options = [{Opt, Val}]

Specifies default options for listen (and - accept) sockets, see inet(3).

+ accept) sockets, see inet(3).

 {inet_dist_use_interface, ip_address()} -

If the host of an Erlang node has several network interfaces, - this parameter specifies which one to listen on. See - inet(3) for the type definition - of ip_address().

+

If the host of an Erlang node has many network interfaces, + this parameter specifies which one to listen on. For the type definition + of ip_address(), + see inet(3).

 - {inet_dist_listen_min, First} + {inet_dist_listen_min, First} and {inet_dist_listen_max, Last} -

See below.

- - {inet_dist_listen_max, Last} - -

Define the First..Last port range for the listener +

Defines the First..Last port range for the listener socket of a distributed Erlang node.

 {inet_dist_listen_options, Opts} -

Define a list of extra socket options to be used when opening the +

Defines a list of extra socket options to be used when opening the listening socket for a distributed Erlang node. - See gen_tcp:listen/2

+ See gen_tcp:listen/2.

 {inet_dist_connect_options, Opts} -

Define a list of extra socket options to be used when connecting to +

Defines a list of extra socket options to be used when connecting to other distributed Erlang nodes. - See gen_tcp:connect/4

+ See gen_tcp:connect/4.

 inet_parse_error_log = silent -

If this configuration parameter is set, no +

If set, no error_logger messages are generated when erroneous lines are found and skipped in the various Inet configuration files.

 inetrc = Filename -

The name (string) of an Inet user configuration file. See - ERTS User's Guide, Inet configuration.

+

The name (string) of an Inet user configuration file. For details, + see section + Inet Configuration + in the ERTS User's Guide.

 net_setuptime = SetupTime

SetupTime must be a positive integer or floating point - number, and will be interpreted as the maximally allowed time + number, and is interpreted as the maximum allowed time for each network operation during connection setup to another - Erlang node. The maximum allowed value is 120; if higher values - are given, 120 will be used. The default value if the variable - is not given, or if the value is incorrect (e.g. not a number), - is 7 seconds.

-

Note that this value does not limit the total connection + Erlang node. The maximum allowed value is 120. If higher values + are specified, 120 is used. Default is 7 seconds if the variable + is not specified, or if the value is incorrect (for example, not a number).

+

Notice that this value does not limit the total connection setup time, but rather each individual network operation during the connection setup and handshake.

 @@ -268,45 +258,44 @@

Specifies the net_kernel tick time. TickTime - is given in seconds. Once every TickTime/4 second, all - connected nodes are ticked (if anything else has been written - to a node) and if nothing has been received from another node - within the last four (4) tick times that node is considered - to be down. This ensures that nodes which are not responding, + is specified in seconds. Once every TickTime/4 second, all + connected nodes are ticked (if anything else is written + to a node). If nothing is received from another node + within the last four tick times, that node is considered + to be down. This ensures that nodes that are not responding, for reasons such as hardware errors, are considered to be down.

The time T, in which a node that is not responding is - detected, is calculated as: where:

+ detected, is calculated as , where:

MinT = TickTime - TickTime / 4 MaxT = TickTime + TickTime / 4 -

TickTime is by default 60 (seconds). Thus, +

TickTime defaults to 60 (seconds). Thus, seconds.

-

Note: All communicating nodes should have the same +

Notice that all communicating nodes are to have the same TickTime value specified.

-

Note: Normally, a terminating node is detected - immediately.

+

Normally, a terminating node is detected immediately.

 shutdown_timeout = integer() | infinity -

Specifies the time application_controller will wait +

Specifies the time application_controller waits for an application to terminate during node shutdown. If the - timer expires, application_controller will brutally - kill application_master of the hanging + timer expires, application_controller brutally + kills application_master of the hanging application. If this parameter is undefined, it defaults to infinity.

 sync_nodes_mandatory = [NodeName] -

Specifies which other nodes must be alive in order +

Specifies which other nodes that must be alive for this node to start properly. If some node in the list - does not start within the specified time, this node will not + does not start within the specified time, this node does not start either. If this parameter is undefined, it defaults to - [].

+ [].

 sync_nodes_optional = [NodeName] -

Specifies which other nodes can be alive in order +

Specifies which other nodes that can be alive for this node to start properly. If some node in this list does not start within the specified time, this node starts anyway. If this parameter is undefined, it defaults to @@ -314,66 +303,65 @@ MaxT = TickTime + TickTime / 4 sync_nodes_timeout = integer() | infinity -

Specifies the amount of time (in milliseconds) this node - will wait for the mandatory and optional nodes to start. If +

Specifies the time (in milliseconds) that this node + waits for the mandatory and optional nodes to start. If this parameter is undefined, no node synchronization is - performed. This option also makes sure that global is + performed. This option ensures that global is synchronized.

 start_dist_ac = true | false

Starts the dist_ac server if the parameter is - true. This parameter should be set to true for - systems that use distributed applications.

-

The default value is false. If this parameter is - undefined, the server is started if the parameter + true. This parameter is to be set to true for + systems using distributed applications.

+

Defaults to false. If this parameter is + undefined, the server is started if parameter distributed is set.

 start_boot_server = true | false

Starts the boot_server if the parameter is true - (see erl_boot_server(3)). - This parameter should be - set to true in an embedded system which uses this - service.

-

The default value is false.

+ (see erl_boot_server(3)). + This parameter is to be set to true in an embedded system + using this service.

+

Defaults to false.

 boot_server_slaves = [SlaveIP] -

If the start_boot_server configuration parameter is +

If configuration parameter start_boot_server is true, this parameter can be used to initialize - boot_server with a list of slave IP addresses. - SlaveIP = string() | atom | {integer(),integer(),integer(),integer()}

+ boot_server with a list of slave IP addresses:

+

+ SlaveIP = string() | atom | {integer(),integer(),integer(),integer()},

where .

-

Examples of SlaveIP in atom, string and tuple form - are:

-'150.236.16.70', "150,236,16,70", {150,236,16,70}.

-

The default value is [].

+

Examples of SlaveIP in atom, string, and tuple form:

+

'150.236.16.70', "150,236,16,70", {150,236,16,70}.

+

Defaults to [].

 start_disk_log = true | false

Starts the disk_log_server if the parameter is - true (see disk_log(3)). - This parameter should be - set to true in an embedded system which uses this service.

-

The default value is false.

+ true (see disk_log(3)). + This parameter is to be set to true in an embedded system + using this service.

+

Defaults to false.

 start_pg2 = true | false +

Starts the pg2 server (see - pg2(3)) if - the parameter is true. This parameter should be set to - true in an embedded system which uses this service.

-

The default value is false.

+ pg2(3)) if + the parameter is true. This parameter is to be set to + true in an embedded system that uses this service.

+

Defaults to false.

 start_timer = true | false

Starts the timer_server if the parameter is - true (see timer(3)). - This parameter should be - set to true in an embedded system which uses this - service.

-

The default value is false.

+ true (see stdlib:timer(3)). + This parameter is to be set to true in an embedded system + using this service.

+

Defaults to false.

 shutdown_func = {Mod, Func} @@ -383,7 +371,7 @@ MaxT = TickTime + TickTime / 4 Func = atom()

Sets a function that application_controller calls - when it starts to terminate. The function is called as: + when it starts to terminate. The function is called as Mod:Func(Reason), where Reason is the terminate reason for application_controller, and it must return as soon as possible for application_controller @@ -394,25 +382,25 @@ MaxT = TickTime + TickTime / 4

See Also -

app(4), - application(3), - code(3), - disk_log(3), - erl_boot_server(3), - erl_ddll(3), - error_logger(3), - file(3), - global(3), - global_group(3), - heart(3), - inet(3), - net_kernel(3), - os(3), - pg2(3), - rpc(3), - seq_trace(3), - timer(3), - user(3)

+

app(4), + application(3), + code(3), + disk_log(3), + erl_boot_server(3), + erl_ddll(3), + error_logger(3), + file(3), + global(3), + global_group(3), + heart(3), + inet(3), + net_kernel(3), + os(3), + pg2(3), + rpc(3), + seq_trace(3), + user(3), + timer(3)

-- cgit v1.2.3