Recently we changed all our spaces in tarantool from memtx to vinyl. But, during load testing we got a error:

Transaction has been aborted by conflict

After, I found this issue. So, we have to use sequence instead of auto_increment. We have big spaces and vinyl not support altering the indexes. But, it turned out precisely index:alter() can be used for sequence.

For example, we have space in vinyl engine:

tarantool> box.schema.space.create('test', {engine=vinyl})
...
tarantool> box.space.test:create_index('primary', {unique=true, parts={1, 'unsigned'}})
...

And we using auto_increment:

tarantool> box.space.test:auto_increment{'foo'}
---
- [1, 'foo']
...
tarantool> box.space.test:auto_increment{'bar'}
---
- [2, 'bar']

If we want use the sequence we should create a sequence for primary index:

    tarantool> box.schema.sequence.create('test_space_primary_seq')
    ---
    - step: 1
      id: 1
      min: 1
      cache: 0
      uid: 1
      max: 9223372036854775807
      cycle: false
      name: test_space_primary_seq
      start: 1
    ...

Value the created sequence must be last value of our primary index:

tarantool> box.sequence.test_space_primary_seq:set(2)
---
...

Set the primary index sequence:

tarantool> box.space.test.index.primary:alter({sequence='test_space_primary_seq'})
---
...

So, we can change all our auto_increment queries to common insert:

tarantool> box.space.test:insert{nil, 'foo'}
---
- [3, 'foo']
...

Info:

Tarantool 1.7.5-238-g39276fe

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Tarantool: don't use auto_increment in the vinyl engine