[TTL] If there is no compaction, the modification to ttl may not take effect

[cangfengzhs]

Please check the FAQ documentation before raising an issue

Describe the bug (required)

create tag ttl_tag2(age int, ttl timestamp) ttl_duration=600, ttl_col="ttl";
insert vertex ttl_tag2(age,ttl) VALUES "1":(10,now());
match (v:ttl_tag2) return v limit 10;  //  visible
alter tag ttl_tag2 ttl_duration=5;
match (v:ttl_tag2) return v limit 10; // not visible
alter tag ttl_tag2 ttl_duration=600;
match (v:ttl_tag2) return v limit 10; // visible

Your Environments (required)

• OS: uname -a
• Compiler: g++ --version or clang++ --version
• CPU: lscpu
• Commit id (e.g. a3ffc7d8)

How To Reproduce(required)

Steps to reproduce the behavior:

1. Step 1
2. Step 2
3. Step 3

Expected behavior

Additional context

[HarrisChu]

is it by design?

[cangfengzhs]

In terms of design, it is right. But functionally, or logically, it is wrong.

[HarrisChu]

agreed..

if the data is not deleted by compaction, we always compare with the latest ttl duration.
if there're 10 tags, and 5 tags have been deleted, and the other 5 have not.
it may make user confused.

[HarrisChu]

marked as known issue

[shanlai]

@abby-cyber please update doc

[whitewum]

@abby-cyber please update doc

I think this is a data error, from the view of a user.

I do not agree to add to doc just as a warning. What is by design? Who designed this data error operation?

@MuYiYong @Sophie-Xie

[critical27]

It is a data error indeed, but it can't be addressed totally. There is a workaround: forbid alter ttl duration if already has one.

[whitewum]

What if this TTL tag is dropped and re-created?

[critical27]

IIRC, drop TTL is achieved by alter as well. I really don't remember this behavior precisely.

[HarrisChu]

update more details in v3.4 rc

1. we could edit the ttl duration in one tag. (also could edit the ttl col)
2. we could not drop and add the same property.

(root@nebula) [(none)]> create space harris(vid_type=fixed_string(10))
Execution succeeded (time spent 9721/23528 us)

Tue, 10 Jan 2023 09:13:34 CST

(root@nebula) [(none)]> use harris
Execution succeeded (time spent 1195/15207 us)

Tue, 10 Jan 2023 09:13:38 CST

(root@nebula) [harris]> create tag ttl_tag2(age int, ttl timestamp) ttl_duration=600, ttl_col="ttl";
Execution succeeded (time spent 5350/18644 us)

Tue, 10 Jan 2023 09:13:40 CST

(root@nebula) [harris]> insert vertex ttl_tag2(age,ttl) VALUES "1":(10,now());
Execution succeeded (time spent 3422/20693 us)

Tue, 10 Jan 2023 09:13:44 CST

(root@nebula) [harris]> match (v:ttl_tag2) return v limit 10;
+-------------------------------------------+
| v                                         |
+-------------------------------------------+
| ("1" :ttl_tag2{age: 10, ttl: 1673313225}) |
+-------------------------------------------+
Got 1 rows (time spent 10824/24590 us)

Tue, 10 Jan 2023 09:13:49 CST

(root@nebula) [harris]> alter tag ttl_tag2 ttl_duration=5;
Execution succeeded (time spent 3936/19855 us)

Tue, 10 Jan 2023 09:13:52 CST

(root@nebula) [harris]> match (v:ttl_tag2) return v limit 10;
+---+
| v |
+---+
+---+
Empty set (time spent 4044/20797 us)

Tue, 10 Jan 2023 09:13:56 CST

(root@nebula) [harris]> alter tag ttl_tag2 ttl_duration=600;
Execution succeeded (time spent 3182/20368 us)

Tue, 10 Jan 2023 09:14:00 CST

(root@nebula) [harris]> match (v:ttl_tag2) return v limit 10;
+-------------------------------------------+
| v                                         |
+-------------------------------------------+
| ("1" :ttl_tag2{age: 10, ttl: 1673313225}) |
+-------------------------------------------+
Got 1 rows (time spent 3734/17573 us)

Tue, 10 Jan 2023 09:14:04 CST

(root@nebula) [harris]> show hosts
+-----------------+-------+----------+--------------+-------------------------------------------+--------------------------------------------+-------------+
| Host            | Port  | Status   | Leader count | Leader distribution                       | Partition distribution                     | Version     |
+-----------------+-------+----------+--------------+-------------------------------------------+--------------------------------------------+-------------+
| "192.168.8.152" | 10030 | "ONLINE" | 77           | "harris:34, nba:34, sf0_1:5, 王者荣耀:4"  | "harris:34, nba:34, sf0_1:24, 王者荣耀:12" | "3.4.0-ent" |
| "192.168.8.152" | 10035 | "ONLINE" | 76           | "harris:33, nba:33, sf0_1:6, 王者荣耀:4"  | "harris:33, nba:33, sf0_1:24, 王者荣耀:12" | "3.4.0-ent" |
| "192.168.8.152" | 10040 | "ONLINE" | 83           | "harris:33, nba:33, sf0_1:13, 王者荣耀:4" | "harris:33, nba:33, sf0_1:24, 王者荣耀:12" | "3.4.0-ent" |
+-----------------+-------+----------+--------------+-------------------------------------------+--------------------------------------------+-------------+
Got 3 rows (time spent 2281/21594 us)

Tue, 10 Jan 2023 09:14:06 CST

(root@nebula) [harris]> alter tag ttl_tag2 drop (ttl)
Execution succeeded (time spent 3059/15864 us)

Tue, 10 Jan 2023 09:16:28 CST

(root@nebula) [harris]> alter tag ttl_tag2 add (ttl timestamp)
[ERROR (-1005)]: Existed!

Tue, 10 Jan 2023 09:16:38 CST

(root@nebula) [harris]>