Troubleshoot HTTP Event Collector

Logging

HTTP Event Collector saves usage data about itself to log files. You can query these usage metrics using Splunk Enterprise or Splunk Cloud to explore usage trends system-wide, per token, per sourcetype, and more, as well as to evaluate HTTP Event Collector performance. Metrics are logged whenever HTTP Event Collector is enabled. HTTP Event Collector is disabled by default, so it will not log data until you enable it.

You can also view HTTP Event Collector error logs in splunkd.log. See enable debug logging for how to enable debugging on your Splunk instance.

Log file location and management

HTTP Event Collector metrics are written to the http_event_collector_metrics.log file located at the following path:

$SPLUNK_HOME/var/log/introspection/splunk/

A new http_event_collector_metrics.log file is created when you start your Splunk Enterprise instance (or log off of and then onto Splunk Cloud). Any existing file with that name is renamed by giving it next higher available numeric extension. For example, if you restart Splunk Enterprise or log off of and onto Splunk Cloud and there exists http_event_collector_metrics.log, http_event_collector_metrics.1, and http_event_collector_metrics.2 files, the http_event_collector_metrics.log file will be renamed http_event_collector_metrics.3 and HTTP Event Collector will begin logging to a new http_event_collector_metrics.log file.

You configure the logging frequency of HTTP Event Collector metrics in the limits.conf file. 60 seconds is the default frequency. HTTP Event Collector continues logging system-level metrics even when there is no data input activity. When there is no activity, you can expect about 200 kilobytes (KB) of metrics log data to be produced every 24 hours. The maximum size of a metrics log file is 25 megabytes (MB). If a log file reaches that limit, the log file is renamed as described in the previous paragraph and a new one is created. Up to five metrics log files can be stored at a time. The props.conf file defines parameters for reading and indexing the metrics log file.

Querying HTTP Event Collector metrics data

HTTP Event Collector metrics data is indexed to the "_introspection" index. To query the accumulated HTTP Event Collector metrics using Splunk, use the following command:

index="_introspection" token

Metrics log data format

HTTP Event Collector metrics data is recorded to the log in JSON format. This means that the log is both easily human-readable and consistent with other Splunk Enterprise or Splunk Cloud log formats. A single entry consists of both input summary metrics (series = http_event_collector) and per-token metrics (series = http_event_collector_token), as shown in the following example:

{  
   "datetime":"09-01-2016 19:21:19.014 -0700",
   "log_level":"INFO",
   "component":"HttpEventCollector",
   "data":{  
      "series":"http_event_collector",
      "transport":"http",
      "format":"json",
      "total_bytes_received":0,
      "total_bytes_indexed":0,
      "num_of_requests":0,
      "num_of_events":0,
      "num_of_errors":0,
      "num_of_parser_errors":0,
      "num_of_auth_failures":0,
      "num_of_requests_to_disabled_token":0,
      "num_of_requests_to_incorrect_url":0,
      "num_of_requests_in_mint_format":0,
      "num_of_ack_requests":0,
      "num_of_requests_acked":0,
      "num_of_requests_waiting_ack":0
   }
}

{  
   "datetime":"08-22-2016 12:38:04.854 -0700",
   "log_level":"INFO",
   "component":"HttpEventCollector",
   "data":{  
      "token_name":"test",
      "series":"http_event_collector_token",
      "transport":"http",
      "format":"json",
      "total_bytes_received":57000,
      "total_bytes_indexed":44000,
      "num_of_requests":1000,
      "num_of_events":1000,
      "num_of_errors":0,
      "num_of_parser_errors":0,
      "num_of_requests_to_disabled_token":0,
      "num_of_requests_in_mint_format":0
   }
}

HEC summary metrics

System-wide summary metrics are always accumulated even if there is no input activity. These metrics are identified by "series":"http_event_collector".

Field	Description	Value
component	HTTP Event Collector metrics data identifier.	HttpEventCollector
data:format	HTTP Event Collector data format.	json
data:num_of_auth_failures	Total number of authentication failures due to invalid token.	unsigned integer
data:num_of_errors	Total number of per-token errors, which include: bad data format no authorization bad authorization connectivity problems	unsigned integer
data:num_of_events	Total number of per-token events received by the HTTP Event Collector endpoint.	unsigned integer
data:num_of_parser_errors	Total number of per-token parser errors due to incorrectly formatted event data.	unsigned integer
data:num_of_requests	Total number of valid per-token individual HTTP(S) requests received by an HTTP Event Collector endpoint. Each request can have one or more data events.	unsigned integer
data:num_of_requests_to_incorrect_url	Total number of requests to an incorrect URL.	unsigned integer
data:num_of_requests_in_mint_format	Total number of requests from Splunk MINT.	unsigned integer
data:num_of_requests_to_disabled_token	Total number of per-token requests to disable token.	unsigned integer
data:series	Metrics data type.	http_event_collector
data:total_bytes_indexed	Total amount of per-token data sent to the indexer.	unsigned integer
data:total_bytes_received	Total amount of per-token data received by calling the /receive/token endpoint.	unsigned integer
data:transport	Data transport protocol for HTTP Event Collector data.	http
datetime	Date and time associated with the data. Format: MM-DD-YYYY HH:MM:SS.SSS +/-GMTDELTA	string
log_level	Log severity level.	INFO

Per-token metrics

In contrast to the system-wide summary metrics, per-token metrics are accumulated only when HTTP Event Collector is enabled. These metrics are identified by "series":"http_event_collector_token".

The [http_input] stanza in the limits.conf file defines the logging interval and maximum number of tokens logged for these metrics.

Field	Description	Value
component	HTTP Event Collector metrics data identifier.	HttpEventCollector
data:format	HTTP Event Collector data format. (Always json for metrics logging.)	json
data:num_of_errors	Number of errors, which include: bad data format no authorization bad authorization connectivity problems	unsigned integer
data:num_of_events	Number of events received by the HTTP Event Collector endpoint.	unsigned integer
data:num_of_parser_errors	Number of parser errors due to incorrectly formatted event data.	unsigned integer
data:num_of_requests	Number of valid individual HTTP(S) requests received by an HTTP Event Collector endpoint. Each request can have one or more data events.	unsigned integer
data:num_of_requests_in_mint_format	Total number of requests from Splunk MINT.	unsigned integer
data:num_of_requests_to_disabled_token	Number of requests to a disabled token.	unsigned integer
data:series	Metrics data type.	http_event_collector_token
data:token_name	Token name.	string
data:total_bytes_indexed	Total amount of data sent to the indexer.	unsigned integer
data:total_bytes_received	Total amount of data received by calling the /receive/token endpoint.	unsigned integer
data:transport	Data transport protocol for HTTP Event Collector data.	http
datetime	Date and time associated with the data. Format: MM-DD-YYYY HH:MM:SS.SSS +/-GMTDELTA	string
log_level	Log severity level.	INFO

Setting up logging with configuration files

Configuration

The limits.conf and props.conf files control metrics data logging and indexing behavior.

limits.conf

The [http_input] stanza in the $SPLUNK_HOME/etc/system/default/limits.conf file controls HTTP Event Collector metrics data logging.

For information about all HTTP Event Collector-related parameters, including those not related to metrics, see the [http_input] stanza documentation on limits.conf in the Splunk Enterprise Admin Manual.

Example

Parameters

Parameter	Default value	Description
max_number_of_tokens	10000	An unsigned integer that represents the maximum number of tokens reported by HTTP Event Collector metrics.
metrics_report_interval	60	An unsigned integer that represents the number of seconds in an HTTP Event Collector metrics report interval.

props.conf

The [http_event_collector_metrics] stanza in the $SPLUNK_HOME/etc/system/default/props.conf file controls reading and indexing the HTTP Event Collector log files.
Example

[source::.../http_event_collector_metrics.log(.\d+)?]
sourcetype = http_event_collector_metrics

...

[http_event_collector_metrics]
SHOULD_LINEMERGE = false
TIMESTAMP_FIELDS = datetime
TIME_FORMAT = %m-%d-%Y %H:%M:%S.%l %z
INDEXED_EXTRACTIONS = json
KV_MODE = none
JSON_TRIM_BRACES_IN_ARRAY_NAMES = true

Parameters

Parameter	Default	Description
SHOULD_LINEMERGE	false	Specifies layout of events per line: true = Allow multiple events in the same line. false = Put multiple events in separate lines.
TIMESTAMP_FIELDS	datetime	Log entry time field name.
TIME_FORMAT	%m-%d-%Y %H:%M:%S.%l %z	Log entry time field format.
INDEXED_EXTRACTIONS	json	Metrics log format. (Always json for metrics logging.)
KV_MODE	none	Key-value data indicator: none = No key-value data. (Always none for metrics logging.)
JSON_TRIM_BRACES_IN_ARRAY_NAMES	true	Whether to trim brace characters from JSON array names

Possible error codes

The following status codes have particular meaning for all HTTP Event Collector endpoints:

Status Code	HTTP status code ID	HTTP status code	Status message
0	200	OK	Success
1	403	Forbidden	Token disabled
2	401	Unauthorized	Token is required
3	401	Unauthorized	Invalid authorization
4	403	Forbidden	Invalid token
5	400	Bad Request	No data
6	400	Bad Request	Invalid data format
7	400	Bad Request	Incorrect index
8	500	Internal Error	Internal server error
9	503	Service Unavailable	Server is busy
10	400	Bad Request	Data channel is missing
11	400	Bad Request	Invalid data channel
12	400	Bad Request	Event field is required
13	400	Bad Request	Event field cannot be blank
14	400	Bad Request	ACK is disabled
15	400	Bad Request	Error in handling indexed fields
16	400	Bad Request	Query string authorization is not enabled

To ensure data is successfully ingested into the Splunk platform, configure your clients with the ability to act on response codes returned by the HEC endpoint. If the client can't take an action based on the resulting response code, data loss might occur.

Monitoring Console

The Monitoring Console provides prebuilt dashboards for HTTP event collector that you can use to investigate your instance's performance.

• For Splunk Cloud, see Monitor your Splunk Cloud Deployment.
• For Splunk Enterprise, see About the Monitoring Console.

The Monitoring Console provides a pre-built dashboard to monitor HTTP Event Collector. See HTTP Event Collector Dashboards in the Monitoring Splunk Enterprise manual.

Detecting scaling problems

If you are experiencing performance slowdowns, or want to speed up your HTTP Event Collector deployment, the following factors can affect performance:

• HTTP vs. HTTPS: There is a significant performance improvement when sending data over HTTP versus sending data over HTTPS.
• Batching: If you batch multiple events into single requests, it can speed up data transmission. Because a request's metadata applies to all events in the request, less data is sent overall. For more information about how event data is packaged, see format events for HTTP Event Collector.
• HTTP Keep-alive: Setting keepalive on your connection can increase performance. As long as the client sending the data supports HTTP 1.1 and is set up to support a persistent connection, you're taking advantage of keep-alive.
• Persistent queues: persistent queuing slows down performance by storing data in an input queue to disk. For more information, see use persistent queues to help prevent data loss.
• Use index-time field extraction: For more information about index-time field extraction, see Create custom fields at index time.