YSQL: DDL command raises unexpected error "Transaction for catalog table write operation 'pg_type' not found"

[d-uspenskiy]

The following test case

@RunWith(YBTestRunnerNonTsanOnly.class)
public class ConcurrentDDL extends BasePgSQLTest {
  private static final Logger LOG = LoggerFactory.getLogger(ConcurrentDDL.class);

  @Test
  public void testConcurrency() throws Exception {
    AtomicBoolean stop = new AtomicBoolean(false);
    AtomicBoolean errorDetected = new AtomicBoolean(false);
    final int threadCount = 20;
    ExecutorService exec = Executors.newFixedThreadPool(20);
    for (int i = 0; i < threadCount; ++i) {
      final Integer idx = i;
      exec.submit(() -> {
        try(Connection c = getConnectionBuilder().withTServer(idx % 3).connect();
            Statement s = c.createStatement()) {
          while (!stop.get()) {
            helper(s, String.format("CREATE TABLE IF NOT EXISTS tt_%d( k int PRIMARY KEY, v int)", idx));
            helper(s, String.format("CREATE INDEX IF NOT EXISTS tt_%d_v ON tt_%d(v)", idx, idx));
            helper(s, String.format("DROP TABLE IF EXISTS tt_%d", idx));
          }
        } catch (Exception e) {
          LOG.error("Unexpected exception", e);
          errorDetected.set(true);
        }
      });
    }
    try(Connection c = getConnectionBuilder().withTServer(0).connect();
      Statement s = c.createStatement()) {
      final int count = 100;
      for (int i = 0; i < count; ++i) {
        helper(s, "CREATE TABLE IF NOT EXISTS t (a INT)");
        helper(s, "DROP TABLE IF EXISTS t");
      }
    }
    stop.set(true);
    exec.shutdown();
    exec.awaitTermination(1, TimeUnit.MINUTES);
    assertFalse(errorDetected.get());
  }

  @Override
  protected Map<String, String> getTServerFlags() {
    Map<String, String> flagMap = super.getTServerFlags();
    flagMap.put("ysql_log_statement", "all");
    return flagMap;
  }

  private static void helper(Statement s, String query) throws SQLException {
    try {
      s.execute(query);
    } catch(SQLException e) {
      final String msg = e.getMessage();
      if (!(msg.contains("Catalog Version Mismatch") || msg.contains("Try again"))) {
        throw e;
      }
    }
  }
}

fails with error

ts1|pid326976|:27271|http://127.237.244.27:12097 2021-08-10 15:46:36.693 MSK [327400] ERROR:  Illegal state: Transaction for catalog table write operation 'pg_type' not found
ts1|pid326976|:27271|http://127.237.244.27:12097 2021-08-10 15:46:36.693 MSK [327400] STATEMENT:  DROP TABLE IF EXISTS tt_12
2021-08-10 15:46:36,694 (pool-4-thread-13) [ERROR - org.yb.pgsql.ConcurrentDDL.lambda$testConcurrency$0(ConcurrentDDL.java:41)] Unexpected exception
org.postgresql.util.PSQLException: ERROR: Illegal state: Transaction for catalog table write operation 'pg_type' not found
        at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2440)
        at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:2183)
        at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:308)
        at org.postgresql.jdbc.PgStatement.executeInternal(PgStatement.java:441)
        at org.postgresql.jdbc.PgStatement.execute(PgStatement.java:365)
        at org.postgresql.jdbc.PgStatement.executeWithFlags(PgStatement.java:307)
        at org.postgresql.jdbc.PgStatement.executeCachedSql(PgStatement.java:293)
        at org.postgresql.jdbc.PgStatement.executeWithFlags(PgStatement.java:270)
        at org.postgresql.jdbc.PgStatement.execute(PgStatement.java:266)
        at org.yb.pgsql.ConcurrentDDL.helper(ConcurrentDDL.java:69)
        at org.yb.pgsql.ConcurrentDDL.lambda$testConcurrency$0(ConcurrentDDL.java:38)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at java.lang.Thread.run(Thread.java:748)