I am working with
- MySQL Cluster 7.2.4
- memcached 1.6
I started memcached service with ndb-caching option:
memcached -E /usr/local/mysql/lib/ndb_engine.so -e "connectstring=10.12.200.117:1186;role=ndb-caching;debug=true" -vv -c 20 -u root
mysql> SELECT * FROM memcache_server_roles where role_name='ndb-caching';
+-------------+---------+---------+---------------------+
| role_name | role_id | max_tps | update_timestamp |
+-------------+---------+---------+---------------------+
| ndb-caching | 3 | 100000 | 2012-03-21 17:53:45 |
+-------------+---------+---------+---------------------+
with role id 3
mysql> SELECT * FROM key_prefixes where server_role_id=3;
+----------------+------------+------------+---------+-------------+
| server_role_id | key_prefix | cluster_id | policy | container |
+----------------+------------+------------+---------+-------------+
| 3 | b: | 0 | caching | demo_ext |
| 3 | t: | 0 | caching | demo_tabs |
| 3 | | 0 | caching | demo_table |
| 3 | d: | 0 | caching | deepak_new |
| 3 | dee: | 0 | caching | deepak_new1 |
+----------------+------------+------------+---------+-------------+
I just looked into demo_tabs container
mysql> SELECT * FROM containers where name='demo_tabs';
+-----------+-------------+-----------------+-------------+----------------+-------+------------------+------------+--------------------+--------------------+
| name | db_schema | db_table | key_columns | value_columns | flags | increment_column | cas_column | expire_time_column | large_values_table |
+-----------+-------------+-----------------+-------------+----------------+-------+------------------+------------+--------------------+--------------------+
| demo_tabs | ndbmemcache | demo_table_tabs | mkey | val1,val2,val3 | flags | NULL | NULL | expire_time | NULL |
+-----------+-------------+-----------------+-------------+----------------+-------+------------------+------------+--------------------+--------------------+
Now I saw the contents in the ndbmemcache.demo_table_tabs table:
select * from ndbmemcache.demo_table_tabs;
mysql> select * from ndbmemcache.demo_table_tabs;
+------+--------------+------+------+-------+-------------+
| mkey | val1 | val2 | val3 | flags | expire_time |
+------+--------------+------+------+-------+-------------+
| 2 | abcdefghijlk | NULL | NULL | NULL | NULL |
+------+--------------+------+------+-------+-------------+
I expect for the key t:2 values abcdefghijlk, but this value is not there in cache -- it's only in the database.
But still I run get t:2 in telnet the connection closes unexpectedly:
[root@cent2 ~]# telnet localhost 11211
Trying 127.0.0.1...
Connected to localhost.localdomain (127.0.0.1).
Escape character is '^]'.
get t:2
Connection closed by foreign host.
[root@cent2 ~]#
The memcached service stopped with error message:
[root@cent2 ~]#memcached -E /usr/local/mysql/lib/ndb_engine.so -e "connectstring=10.12.200.117:1186;role=ndb-caching;debug=true" -vv -c 20 -u root
..........................
..........................
worker.1 schedule():1.0 placed on send queue.
cl0.conn1.send run_ndb_send_thread():Sent 1.0
cl0.conn1.poll run_ndb_poll_thread(): ** adding 1.0 to wait group **
cl0.conn1.poll run_ndb_poll_thread():Polling 1.0
cl0.conn1.poll callback_main():Success.
cl0.conn1.poll worker_finalize_read():1.0
cl0.conn1.poll --> build_hash_item()
cl0.conn1.poll build_hash_item():nbytes: 21 ncopied: 16
Segmentation fault
[root@cent2 ~]#
Why is this service closing unexpectedly?
