When you use the Tealeaf Portal search when the canisters go down for maintenance the messaging is pretty egregious. Complex error messages are given to the end-user like "Error, index was out of range." and "Error parsing search result XML: XML document must of a top level element."

This can be solved by treating the canisters like a database table. When a canister goes down for maintenance, MAINT service notifies the Portal Search service (AuthMaster) a canister is locked for maintenance, with expected duration (based on last maint cycle). When the Portal search service runs it excludes all 'locked' canisters and gives a banner notice at the top that several "search canisters" are down for maintenance with their ETA listed for expected return to online. At the end of maintenance, the canister search service again signals to Portal Search Service it is done and can unlock search service for itself. This signal will keep checking until the Portal search service returns a confirm it has unlocked.