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Module otter

otter API module.

Description

otter API module. Use the API in this module to interact with the otter application. If you want to specifically use the process dictionary API, use the otter_pdict_api module instead. The API is broken down into 3 sections. The Span API, Snapshot/Count API and Config API.

Span API

These API calls allow you to create and manage spans. These are:
start/1, start/2, start/3
finish/1
ids/1
log/2, log/3
tag/3, tag/4

Snapshot/Count API

When finish/1 is called then the completed span is passed to a configurable filter. The filter can check the Span tags as well as the name and duration of the span and use the information to decide to send the Span to the trace collector (Zipkin supported) and/or increase counters based on values of the tags and store the last Span for the counters. This latter is particularly useful for troubleshooting e.g. error events when increase of the corresponding counter is noticed. These snapshots (referred as Snap) and counters can be retrieved, managed with this API. These are:
counter_list/0
counter_snapshot/1
counter_delete/1
counter_delete_all/0

Config API

The default implementation uses the application environment to store configuration. There is a simple wrapper module to interface with configuration store (otter_config). To implement other config persistence, the module should be replaced with another one providing the same simple read/write API functions.
WARNING : In the default implementation using the application environment, so the write function is NOT persistent. In case of node restart and/or application reload the configuration will be reset to whatever environment is defined in the release (sys) config or app file. There is an example configuration provided in the otter.app file as a reference. These are:
config_list/0
config_read/1
config_read/2
config_write/2

Function Index

config_list/0
config_read/1
config_read/2
config_write/2
counter_delete/1
counter_delete_all/0
counter_list/0
counter_snapshot/1
finish/1Ends a span and prepares it for potential delivery to the backend based on filtering rules.
ids/1Returns the TraceId and SpanId for a given span.
log/2Adds a log message to a span.
log/3
start/1Starts a span with the specified name.
start/2Starts a span with the specified name and TraceId.
start/3Starts a child span with the specified name, TraceId and ParentId.
tag/3Adds a tag to a span.
tag/4Adds a tag to a span with a given service.

Function Details

config_list/0

config_list() -> term()

config_read/1

config_read(Key::atom()) -> term()

config_read/2

config_read(Key::atom(), Default::term()) -> term()

config_write/2

config_write(Key::atom(), Value::term()) -> ok

counter_delete/1

counter_delete(Key::list()) -> ok

counter_delete_all/0

counter_delete_all() -> ok

counter_list/0

counter_list() -> [{list(), integer()}]

counter_snapshot/1

counter_snapshot(Key::list()) -> term()

finish/1

finish(Span::span()) -> ok

Ends a span and prepares it for potential delivery to the backend based on filtering rules

ids/1

ids(Span::span()) -> {trace_id(), span_id()}

Returns the TraceId and SpanId for a given span.

log/2

log(Span::span(), Text::info()) -> span()

Adds a log message to a span

log/3

log(Span::span(), Text::info(), Service::service()) -> span()

start/1

start(Name::info()) -> span()

Starts a span with the specified name. Automatically generates a TraceId.

start/2

start(Name::info(), TraceId::integer()) -> span()

Starts a span with the specified name and TraceId

start/3

start(Name::info(), TraceId::integer(), ParentId::integer()) -> span()

Starts a child span with the specified name, TraceId and ParentId

tag/3

tag(Span::span(), Key::info(), Value::info()) -> span()

Adds a tag to a span. If the tag already exists, its value will be overwritten

tag/4

tag(Span::span(), Key::info(), Value::info(), Service::service()) -> span()

Adds a tag to a span with a given service. If the tag already exists, its value will be overwritten

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Generated by EDoc, Apr 14 2017, 04:39:45.