The minimum reference server specification for a Splunk indexer is 12 CPU cores, 12GB RAM, and 800 IOPS. This specification is based on the assumption that the indexer will handle an average indexing volume of 100GB per day, with a peak of 300GB per day, and a typical search load of 1 concurrent search per 1GB of indexing volume. The other specifications are either higher or lower than the minimum requirement. For more information, see [Reference hardware] in the Splunk documentation.

Configurations from the deployer are merged into the SPLUNK_HOME/etc/apps/APP_HOME/local directory on the search head cluster member. The deployer distributes apps and other configurations to the search head cluster members in the form of a configuration bundle. The configuration bundle contains the contents of the SPLUNK_HOME/etc/shcluster/apps directory on the deployer. When a search head cluster member receives the configuration bundle, it merges the contents of the bundle into its own SPLUNK_HOME/etc/apps directory. The configurations in the local directory take precedence over the configurations in the default directory. The SPLUNK_HOME/etc/system/local directory is used for system-level configurations, not app-level configurations. The SPLUNK_HOME/etc/apps/search/default directory is used for the default configurations of the search app, not the configurations from the deployer.

Explanation/Reference: https://answers.splunk.com/answers/657187/map-command-field-not-being-evaluated.html

Explanation
The following may explain the problem of why a colleague cannot see the src_ip field in their search results:
The field was extracted as a private knowledge object, and the colleague did not explicitly use the field in the search and the search was set to Fast Mode. A knowledge object is a Splunk entity that applies some knowledge or intelligence to the data, such as a field extraction, a lookup, or a macro. A knowledge object can have different permissions, such as private, app, or global. A private knowledge object is only visible to the user who created it, and it cannot be shared with other users. A field extraction is a type of knowledge object that extracts fields from the raw data at index time or search time. If a field extraction is created as a private knowledge object, then only the user who created it can see the extracted field in their search results. A search mode is a setting that determines how Splunk processes and displays the search results, such as Fast, Smart, or Verbose. Fast mode is the fastest and most efficient search mode, but it also limits the number of fields and events that are displayed. Fast mode only shows the default fields, such as _time, host, source, sourcetype, and
_raw, and any fields that are explicitly used in the search. If a field is not used in the search and it is not a default field, then it will not be shown in Fast mode. The events are tagged as communicate, but are missing the network tag, and the Typing Queue, which does regular expression replacements, is blocked, are not valid explanations for the problem. Tags are labels that can be applied to fields or field values to make them easier to search. Tags do not affect the visibility of fields, unless they are used as filters in the search. The Typing Queue is a component of the Splunk data pipeline that performs regular expression replacements on the data, such as replacing IP addresses with host names. The Typing Queue does not affect the field extraction process, unless it is configured to do so