Quick Caveats - ServiceNow development

[Wasif]

• There is a table rotation applied to all heavy-weight tables like the log tables in ServiceNow, so the data for reconciliation will be limited. Need to be aware when debugging the data. For some tables like ecc_event, ecc_queue, sysevent- there are 7 rotations/shards defined per day- so max 7 days of data can be viewed, for others like the syslog, syslog_transaction- there are 8 rotations/shards defined per week- so max 56 days of data can be viewed (could be lower as 1 shard is reserved for logistics)

• The Node logs do not show any browser activities; for stubborn browser issues, it is advisable to extract the HAR files (Http ARchive) from the browser for detailed investigation. For instance this can be used for say SSO issues etc

• The sys_mod_count (Updates) field only increments when there is some update on the record. Why is that statement important because say for instance If there’s a custom table being updated by integration, and only a custom field of ‘HTTP Status’ is getting updated and there’s additional logic on this table’s sys_mod_count to do retrigger for failures, and the integration is receiving 404, so basically the only update in the table is one field with the same value- this will not increment the ‘sys_mod_count’ count, and hence the subsequent logic will fail.

• When trying to write an ACL (especially script ACL) for a table being used in GlideAggregate, make sure the relevant field is part of the groupBy clause, else the ACL may not be honoured

• Be aware when extending the table, as some of the configuration will be applied to the child tables like business rules, client script/ ui policies (Inherit flag as true), ACLs (parent table ACL if child table ACL not there), Flow (if marked to run for extended tables), Notifications (other than Record trigger)

• Take caution while creating a JSON payload for an outbound integration when using ‘setStringParameterNoEscape’ and not using JSON.stringify(). Why? The json serialization process caters to escaping json special characters, but when the payload structure is directly being used in the Rest Message with parameters being set by the ‘setStringParameterNoEscape’, the json special characters are not escaped and can cause issue at runtime!

• While using Transform Maps along with the Import Set API, and there are multiple maps for a single import set table, all will run in any order. The ‘order’ field is not honored. Be cautious of what is intended wrt configuration.

• When using system properties to store a JSON object, make sure to use JSON.parse() function before using this object as this is stored as a string, so would need to convert to an object first, before extracting any value

Have you guys observed any caveats/ quirks during your ServiceNow developments?
Do share below!