Redis: Backup and Restore [ full DB and single key ]

Here are the processes to backup and restore data from and to the Redis server. Though the restore and back is not a frequently used process, but this becomes crucial in certain use cases. Also moving data from one Redis server to another is a very handy process when we need that. Here we have discussed 2 processes for the backup and restoration of the Redis server.

JavaScript: “use strict” – [strict mode]

“use strict” directive enables a strict operating context/mode for the code. This helps us to identify potential exceptions and makes debugging easier. In strict mode, we are notified about code that would trigger some weird behavior or fail silently. To enable the strict mode for the whole script, add the string “use strict” at the top of the script.

Redis Command: LSET

Change/replace value at a specific index of a list. For the command to work there should be an existing list, with some items and we can only change items that are already set(have an index). Both positive and negative indexes will work for this command. Index is zero(0) based. So the first item is considered at index Zero(0).

Redis Command: LPOP

LPOP removes the first element from the Left/HEAD of the list and then returns it. Count is an optional argument provided for the command, this is used to pop multiple items. If the list has no element left after executing the LPOP command, then the list is deleted after the item(s) popped.

Redis Command: LMPOP

LMPOP command pops one or more items from list(s). This operation can be performed on multiple lists. In case of multiple lists, the pop operation will be performed on the first non-empty list. This command is useful when we have multiple lists serving similar purposes, and we want to pop items from any of the lists if there are items in it.

Redis Command: LPOS

Get the index of item(s) in the list, which matches the provided item. Operation can be performed starting from the HEAD or from the TAIL. This command is useful for checking the position/index of an item in the list, and also useful for checking the existence of an item in the list. Index of the list item is Zero based. The first item is at index Zero(0). If the command does not return (nil). Instead, return some index value (can be zero) which means the item exists in the list.