ILM: Time definitions and processes in a single picture
As an ILM user, we come across so many processes triggered at different instants of time and data is handled accordingly. In my previous blog Information Lifecycle Management(ILM) : Various Time Definitions, have explained different time periods used for in ILM. A picture with the information will help to understand better. The picture below has different sections/processes during the life cycle of data.
Data Lifecycle (Green box)
In lifecycle of data, from its creation to business complete it is very much actively used. After business complete, for many reasons it would remain in database.
After a period of time(residence period), the data is archived and moved into archive file, then deleted from database. The data is retained in archive file for a period of time (retention period).
After a certain time, the archive file will also be deleted. This would ensure the data is deleted permanently without any persistence anywhere. Data goes through different phases, processes from its creation to deletion.
1 – Data Creation
2 – Reaches business complete
3 – End of Residence Time
4 – After archive process, data is deleted from DB and archive file is moved to store
5 – Expiration Date (retention period). This is determined during archiving process using ILM retention rule.
6 – Mandatory Destruction date. This is determined during archiving process using ILM retention rule.
Data Residing At (Grey box)
During the above phases/times, the data resides at different places. From its creation time to time it is archived, it exists in the Database. After archiving is triggered, the data is put into archive file, the file is moved to store and data is deleted from DB.
The same data would now exists only in archive file at store.
Process (Blue box)
Different processes are triggered to handle data which is shown here.
10 – Archiving process which is followed by deletion of data from DB. Data should have completed residence period to be archived.
11 – Store process. The archive file is moved into store(compliant store)
12 – Destruction Process can be triggered on these archive files. This would permanently delete the data. File should be stored then only can be triggered destruction run on this file.
Period (Red box)
With ILM, we use different periods for calculation and set the properties on the files as shown.
In ILM rules, one maintains residence period, retention periods – min and max, reference time and unit. Using these these period are defined and necessary actions are allowed.
7 – Residence Period. This is taken from ILM residence Rule. Till this period is complete, data cannot be archived.
8 – Minimum Retention period. This is taken from minimum retention period value from ILM retention rule. This date is determined during the archiving process.
Till this period is complete, the data in archive file cannot be destroyed. This is set as a property in archive file in store.
9 – Maximum retention period. This is derived from maximum retention period value from ILM retention rule. After this period is complete, the data must be destroyed.
Possible Actions(Yellow box)
The possible actions in relation to its status in its lifecycle is shown.
13 – Time period in which the data cannot be archived. This is defined by residence period.
14 – Time period in which the data cannot be destroyed. This is defined by minimum retention period 
15 – Time period during which user can trigger permanent deletion of data. This is defined by maximum retention period .
16 – Time after which the data MUST be destroyed. This is also defined by maximum retention period.
With this you will have a clear understand on the processes to be triggered, ILM rules to be maintained for your requirements.