An IMS has a byte saving equal to the size of the object minus the bytes required for the IMS reply. Useful might be the concept of Hit Bytes and Miss Bytes with IMS contributing to both. While these would swell logs considerably, they are excellent performance measurement tools for cache administrators. Vendors should provide a log format option to show all such information. Encoding the field values as numbers with sting values in the meta-data would reduce the size increase.
Different vendors talk about similar issues differently.
The methods which are used, or a set of procedures need some standardization. There is also a need for a commonly acceptable taxonomy. The issue of standardized computational methods and comparable results was raised on WREC - the need to have a standard for log file summaries. A useful technique is to grab regular information and display an average of the last half-hour, hour, . By gathering stats regularly and averaging over a period of time, spike behaviour is prevented from skewing data.