Fail to recover XA Transaction on startup when xa log is not flushed and server is down

[tankilo]

• dble version：
• preconditions ：
  no
• configs：

schema.xml

<table name="xa_test" dataNode="dn1,dn2" rule="sharding-by-mod2" primaryKey="ID"/>

rule.xml

<tableRule name="sharding-by-mod2">
        <rule>
            <columns>id</columns>
            <algorithm>hashmod2</algorithm>
        </rule>
    </tableRule>
    <function name="hashmod2" class="Hash">
        <property name="partitionCount">2</property>
        <property name="partitionLength">1</property>
    </function>

server.xml

• steps：

step1. set breakpoint in method com.actiontech.dble.backend.mysql.nio.handler.transaction.xa.XACommitNodesHandler#executeCommit

step 2. executing following command via mysql shell

set xa=1;
delete from xa_test;

step 3. when program stops at the above breakpoint, kill program

{"id":"'Dble_Server.server_01.786'","state":"12","participants":[{"host":"localhost","port":"3306","p_state":"2","expires":0,"schema":"db2"},{"host":"localhost","port":"3306","p_state":"2","expires":0,"schema":"db1"}]}

step 4. restart dble server, dble failed to recover this prepared transaction.

• expect result：

  1. transaction should be rollback

• real result：

  1. transaction is not rollbacked.

• supplements：
  1.

/label ~BUG

[FlyingMao]

Recurring steps from tester：

• dble version：
  dble-2.19.03.0-bbc1097eae1f4e037d1aaf6bbe3d5f77de7d7c87-20190418142931
• preconditions ：

create table sharding_4_t1(id int,name char);

• configs：

schema.xml

<schema name="schema1" sqlMaxLimit="100">
<table name="sharding_4_t1" dataNode="dn1,dn2,dn3,dn4" rule="hash-four" />
</schema>
    <dataNode name="dn1" dataHost="10.186.65.64" database="db1"/>
    <dataNode name="dn2" dataHost="10.186.65.65" database="db1"/>
    <dataNode name="dn3" dataHost="10.186.65.64" database="db2"/>
    <dataNode name="dn4" dataHost="10.186.65.65" database="db2"/>

rule.xml

server.xml

• steps：
  step1. start btrace to trace the dble, BtraceXaDelay.java download here
  BtraceXaDelay.java.txt
  (remove the postfix .txt by yourself)

setp2. execute xa in dble

mysql> set autocommit=0;
mysql> set xa=on;
mysql> insert into sharding_4_t1 values(1,1),(2,2),(3,3),(4,4);
mysql> commit;

step3. restart dble when btrace prints "before xa prepare..." at the second time

step4. execute sql in dble

use schema1;
delete from sharding_4_t1;

• expect result：
  1.

mysql> delete from sharding_4_t1;
Query OK, 0 rows affected (0.06 sec)

• real result：
  1. hang when execute delete from sharding_4_t1 in dble
• supplements：
  1.

/label ~BUG

[FlyingMao]

verified version： dble-9.9.9.9-c5a6bb17a1c8cd191894a01046c0d7c13c6740e4-20190531030545