How :sql_last_value works with jdbc_page_size?

[vitaliikobrin]

I created logstash config to index data from MySQL DB in Elasticsearch by schedule.
Here is my config:
> input {

  jdbc {
    jdbc_connection_string => "jdbc:mysql://mysql:3306/smartlikes_staging"
    jdbc_user => "root"
    jdbc_password => ""
    jdbc_driver_library => "jdbc-driver.jar"
    jdbc_driver_class => "com.mysql.jdbc.Driver"
    jdbc_page_size => 100000
    jdbc_paging_enabled => true
    use_column_value => true
    tracking_column => "updatedat"
    tracking_column_type => "timestamp"
    schedule => "*/2 * * * *"
    last_run_metadata_path => "/configs/products/.logstash_jdbc_last_run"
    statement => "SELECT id, title, brand, description FROM products WHERE updatedAt > :sql_last_value ORDER BY id"
  }
}
filter {
    mutate {
        add_field => { "[@metadata][product_id]" => "%{id}" }
    }
    mutate {
        remove_field => ["id"]
    }
}
output {
  stdout { codec => json_lines }
  elasticsearch {
    "hosts" => "elasticsearch:9200"
    "index" => "products"
    "doc_as_upsert" => true
    "action" => "update"
    "document_type" => "_doc"
    "document_id" => "%{[@metadata][product_id]}"
  }
}

The problem is:
When I run Logstash I expect that it will load all items from the DB match the query (including pagination) and will send them page after page to the ES. And it will happen every 2 minutes. But actually what I have is: it runs approximately each 5 minutes and sends only one page to the ES at once. So, if I start Logstash and there is "--- 2019-04-03 00:00:00.000000000 Z" in .logstash_jdbc_last_run file it loads first 100.000 items and sends them to the ES. The value in .logstash_jdbc_last_run has not changed. Then it starts again after 5 minutes and sends next 100.000 items to the ES.
When it finished, the value in .logstash_jdbc_last_run file has been successfully updated to the latest actual value from updatedAt column (that is ok).

It's not critically though. At least I can increase page size and make it run often. But seems something is going wrong here or my config is invalid.