Spring OAuth2: DuplicateKeyException when using JdbcTokenStore and DefaultTokenServices under heavy load : <p>As mentioned in the title, I'm experiencing the issue, when the same client is querying the token endpoint concurrently (two processes requesting token for the same client at the same time).</p>

<p>The message in the logs of the auth server looks like this:</p>

<pre><code>2016-12-05 19:08:03.313  INFO 31717 --- [nio-9999-exec-5] o.s.s.o.provider.endpoint.TokenEndpoint  : Handling error: DuplicateKeyException, PreparedStatementCallback; SQL [insert into oauth_access_token (token_id, token, authentication_id, user_name, client_id, authentication, refresh_token) values (?, ?, ?, ?, ?, ?, ?)]; ERROR: duplicate key value violates unique constraint "oauth_access_token_pkey"
      Detail: Key (authentication_id)=(4148f592d600ab61affc6fa90bcbf16f) already exists.; nested exception is org.postgresql.util.PSQLException: ERROR: duplicate key value violates unique constraint "oauth_access_token_pkey"
      Detail: Key (authentication_id)=(4148f592d600ab61affc6fa90bcbf16f) already exists.
</code></pre>

<p>I'm using PostgreSQL with table like this:</p>

<pre><code>CREATE TABLE oauth_access_token
(
  token_id character varying(256),
  token bytea,
  authentication_id character varying(256) NOT NULL,
  user_name character varying(256),
  client_id character varying(256),
  authentication bytea,
  refresh_token character varying(256),
  CONSTRAINT oauth_access_token_pkey PRIMARY KEY (authentication_id)
)
</code></pre>

<p>And my application looks like that:</p>

<pre><code>@SpringBootApplication
public class OAuthServTest {
   public static void main (String[] args) {
      SpringApplication.run (OAuthServTest.class, args);
   }

   @Configuration
   @EnableAuthorizationServer
   @EnableTransactionManagement
   protected static class OAuth2Config extends AuthorizationServerConfigurerAdapter {

      @Autowired
      private AuthenticationManager authenticationManager;

      @Autowired
      private DataSource            dataSource;

      @Bean
      public PasswordEncoder passwordEncoder ( ) {
         return new BCryptPasswordEncoder ( );
      }

      @Override
      public void configure (AuthorizationServerEndpointsConfigurer endpoints) throws Exception {
         endpoints.authenticationManager (authenticationManager);
         endpoints.tokenServices (tokenServices ( ));
      }

      @Override
      public void configure (ClientDetailsServiceConfigurer clients) throws Exception {
         clients.jdbc (this.dataSource).passwordEncoder (passwordEncoder ( ));
      }

      @Override
      public void configure (AuthorizationServerSecurityConfigurer oauthServer) throws Exception {
         oauthServer.passwordEncoder (passwordEncoder ( ));
      }

      @Bean
      public TokenStore tokenStore ( ) {
         return new JdbcTokenStore (this.dataSource);
      }

      @Bean
      @Primary
      public AuthorizationServerTokenServices tokenServices ( ) {
         final DefaultTokenServices defaultTokenServices = new DefaultTokenServices ( );
         defaultTokenServices.setTokenStore (tokenStore ( ));
         return defaultTokenServices;
      }

   }
}
</code></pre>

<p>My research always lead me to <a href="https://github.com/spring-projects/spring-security-oauth/issues/276" rel="noreferrer">this problem</a>. But this bug was fixed a long time ago and I'm on the latest version of Spring Boot (v1.4.2).</p>

<p>My guess is that I'm doing something wrong and the retrieval of the token in <a href="https://github.com/spring-projects/spring-security-oauth/blob/2.0.12.RELEASE/spring-security-oauth2/src/main/java/org/springframework/security/oauth2/provider/token/DefaultTokenServices.java" rel="noreferrer">DefaultTokenServices</a> is not happening in the transaction?</p>
