Max value for TTL in cassandra

Question

What is the maximum value we can assign to TTL ?

In the java driver for cassandra TTL is set as a int. Does that mean it is limited to Integer.MAX (2,147,483,647 secs) ?

We are talking about how many years? Do you really need somthing bigger than that? — Raul Guiu, Nov 10 '14 at 16:01
This is about 68 years ... do you plan Cassandra in production within 68 years? Even if you're right I don't think this problem will be handled by you :-) — Carlo Bertuccini, Nov 10 '14 at 17:02

score 10 · Accepted Answer · answered Nov 11 '14 at 20:34

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The maximum TTL is actually 20 years. From org.apache.cassandra.db.ExpiringCell:

public static final int MAX_TTL = 20 * 365 * 24 * 60 * 60; // 20 years in seconds

I think this is verified along both the CQL and Thrift query paths.

answered Nov 11 '14 at 20:34

Caleb Rackliffe

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For reference `Integer.MAX_VALUE` as seconds is equivalent to 68.0511 years. – Sam Berry Sep 16 '15 at 12:27

score 0 · Answer 2 · answered Nov 29 '18 at 12:03

I don't know why do you need this but default TTL is null in Cassandra which means it won't be deleted until you force.

One very powerful feature that Cassandra provides is the ability to expire data that is no longer needed. This expiration is very flexible and works at the level of individual column values. The time to live (or TTL) is a value that Cassandra stores for each column value to indicate how long to keep the value.

The TTL value defaults to null, meaning that data that is written will not expire.

https://www.oreilly.com/library/view/cassandra-the-definitive/9781491933657/ch04.html

score 0 · Answer 3 · answered Jan 13 '22 at 19:42

20 years max TTL is not correct anymore. As per Cassandra news read this notice:

PLEASE READ: MAXIMUM TTL EXPIRATION DATE NOTICE (CASSANDRA-14092)

The maximum expiration timestamp that can be represented by the storage engine is 2038-01-19T03:14:06+00:00, which means that inserts with TTL thatl expire after this date are not currently supported. By default, INSERTS with TTL exceeding the maximum supported date are rejected, but it's possible to choose a different expiration overflow policy. See CASSANDRA-14092.txt for more details.

Prior to 3.0.16 (3.0.X) and 3.11.2 (3.11.x) there was no protection against INSERTS with TTL expiring after the maximum supported date, causing the expiration time field to overflow and the records to expire immediately. Clusters in the 2.X and lower series are not subject to this when assertions are enabled. Backed up SSTables can be potentially recovered and recovery instructions can be found on the CASSANDRA-14092.txt file.

If you use or plan to use very large TTLS (10 to 20 years), read CASSANDRA-14092.txt for more information.

Max value for TTL in cassandra

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