2 successful creates for a resource of the same name may happen

[ranchyang96]

Here is a problem we encountered recently. We use kine for database access and operations. The application would frequently create/delete a specific resource. At high loads, multiple threads/requests try to create a specific resource with the same name at the same time. If this happens right after the specific resource is deleted, there would be a slight chance that 2 create of the resource with the same name would succeed at almost the same time. It happens because the kine table has name and prev_revision as unique keys. The 2 creates uses the same name but different prev_revisions. The earlier one would use the recently-deleted revision and the latter one would use 0. Is my analysis correct? Anyone ever encountered the same problem?

[brandond]

What database engine are you using? Are you sure that you have all the correct indexes as Kine creates on startup? The only time I've ever seen this, the reporter was manually creating the Kine database and table but neglected to also create the correct indexes and constraints.

[ranchyang96]

We use mysql and here is the table creation command:
CREATE TABLE kine (
id int(11) NOT NULL AUTO_INCREMENT,
name varchar(630) CHARACTER SET ascii DEFAULT NULL,
created int(11) DEFAULT NULL,
deleted int(11) DEFAULT NULL,
create_revision int(11) DEFAULT NULL,
prev_revision int(11) DEFAULT NULL,
lease int(11) DEFAULT NULL,
value mediumblob,
old_value mediumblob,
PRIMARY KEY (id),
UNIQUE KEY kine_name_prev_revision_uindex (name,prev_revision),
KEY kine_name_index (name),
KEY kine_name_id_index (name,id),
KEY kine_id_deleted_index (id,deleted),
KEY kine_prev_revision_index (prev_revision)
) ENGINE=InnoDB AUTO_INCREMENT=418778696 DEFAULT CHARSET=utf8

And the version of kine we are using is commit 99a527e. I briefly checked the following commits but haven't found related fixes. Or is there something I missed?
Any help would be greatly appreciated.

[brandond]

Can you reproduce this:

1. On the most recent version of kine
2. Using Kubernetes

Kine implements only the bits of etcd required for use as a Kubernetes datastore. If you are using it as a generic etcd datastore in ways that differ from how the Kubernetes API Server interacts with etcd, exact compliance with etcd is not guaranteed.