Hello,

We are experiencing serious problems with this error with version 4.1.9: ERROR 1015 (HY000): Can't lock file (errno: 4006)

In version 4.1.8 it was: ERROR 1297 (HY000): Got temporary error 4006 'Connect failure - out of
connection objects (increase MaxNoOfConcurrentTransactions)' from ndbcluster

We tried to increase the parameter value in the configuration file, but the only
change is that the cluster stops working after more queries than before, but it
stops. It looks like transactions are not closed once finished. The parameters now are: MaxNoOfConcurrentOperations = 1048576 MaxNoOfConcurrentTransactions = 131072 (see full config file below) To make it work again we must leave the cluster idle for a couple of minutes. We
didn't find a better solution yet.

We are testing the system by sending about 100.000 (100 concurrent) http
requests to a front-end (apache) which then connects to the cluster backend. We have peaks of 400/500 queries per second on each working node. (we are setting up an adserver which will have to serve more than 7mil bans per
day).

Thank you all for any suggestion. gian tech at ipfrom dot com

Some info: -- NDB Cluster -- Management Client -- ndb_mgm> show Connected to Management Server at: 10.0.91.118:1186 Cluster Configuration

--------------------- [ndbd(NDB)] 2 node(s) id=2 @10.0.91.119 (Version: 4.1.9, Nodegroup: 0, Master) id=3 @10.0.91.120 (Version: 4.1.9, Nodegroup: 0)

[ndb_mgmd(MGM)] 1 node(s) id=1 @10.0.91.118 (Version: 4.1.9)

[mysqld(API)] 3 node(s) id=4 @10.0.91.118 (Version: 4.1.9) id=5 @10.0.91.120 (Version: 4.1.9) id=6 @10.0.91.119 (Version: 4.1.9)

This is our config.ini: [NDBD DEFAULT] NoOfReplicas = 2 [MYSQLD DEFAULT] [NDB_MGMD DEFAULT] [TCP DEFAULT] # Managment Server [NDB_MGMD] HostName = 10.0.91.118 # the IP of THIS SERVER # Storage Engines [NDBD] HostName = 10.0.91.119 # the IP of the FIRST SERVER DataDir = /var/lib/mysql MaxNoOfConcurrentOperations = 1048576 MaxNoOfConcurrentTransactions = 131072 [NDBD] HostName = 10.0.91.120 # the IP of the SECOND SERVER DataDir = /var/lib/mysql MaxNoOfConcurrentOperations = 1048576 MaxNoOfConcurrentTransactions = 131072 # 3 MySQL Clients # I personally leave this blank to allow rapid changes of the mysql clients; # you can enter the hostnames of the above two servers here. I suggest you dont. [MYSQLD] [MYSQLD] [MYSQLD]