I search for a variable that I can increase in the server that I don't get any more this error: Node 2 missed heartbeat 2 Node 3 Disconnected Node 2 Disconnected I don't find anything. Regards,

I have an NDB cluster which consists of 4 data nodes. Some of the configuration parameters and system resources as : CPU: 32 RAM: 128GB Replication factor: 2 Data memory: 70GB Index memory: 10GB I am planning to extend cluster capacity. I have two options to achieve this: 1. I can add more RAM to data nodes so data memory and index memory will be able to double up 2. I can add 4 data nodes more to cluster so total data memory and index memory increases too I am not sure which one is a better solution while extending cluster capacity. If I choose first option data size stored per node will be bigger. On the other hand what about 140GB DataMemory per data node? Are there any recommended maximum value for DataMemory ve IndexMemory parameters?

I was able to setup a new mysql cluster, with total 6 VMs. New requirement is to add memcache plugin to mysql cluster, memcache failing to start with this error message WARNING -- Failed to allocate nodeid for API at 192.168.1.100. Returned error: 'No free node id found for mysqld(API).' . Here is my existing setup. 192.168.1.100 Management1 192.168.1.101 Management2 192.168.1.102 datanode1 192.168.1.103 datanode2 192.168.1.104 sqlnode1 192.168.1.105 sqlnode2 I am trying to run memcached on existing sql nodes > sqlnode1 & sqlnode2 Here is the configuration on management nodes Management1, Management2 [ndb_mgmd default] DataDir=/mysql/data [ndbd default] NoOfReplicas=2 LockPagesInMainMemory=1 DataMemory=25G IndexMemory=5G NoOfFragmentLogFiles=300 DataDir=/mysql/data MaxNoOfConcurrentOperations=1000000 SchedulerSpinTimer=400 SchedulerExecutionTimer=100 RealTimeScheduler=1 MaxNoOfTables=1024 MaxNoOfOrderedIndexes=256 [ndb_mgmd] HostName=192.168.1.100 NodeId=51 [ndb_mgmd] HostName=192.168.1.101 NodeId=52 [ndbd] HostName=192.168.1.102 NodeId=53 [ndbd] HostName=192.168.1.103 NodeId=54 [mysqld] HostName=192.168.1.104 NodeId=55 [mysqld] HostName=192.168.1.105 NodeId=56 [mysqld] HostName=192.168.1.104 NodeId=57 [mysqld] HostName=192.168.1.105 NodeId=58 Here is configuration file /etc/my.conf on data & sql nodes datenode1, datanode2, sqlnode1, sqlnode2. [mysqld] ndbcluster ndb-connectstring=192.168.1.100,192.168.1.101 datadir=/mysql/data socket=/var/lib/mysql/mysql.sock symbolic-links=0 log-error=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid [mysql_cluster] ndb-connectstring=192.168.1.100,192.168.1.101 current status of cluster. #ndb_mgm -e show Connected to Management Server at: 192.168.1.100:1186 Cluster Configuration --------------------- [ndbd(NDB)] 2 node(s) id=53 @192.168.1.102 (mysql-5.7.19 ndb-7.5.7, Nodegroup: 0) id=54 @192.168.1.103 (mysql-5.7.19 ndb-7.5.7, Nodegroup: 0, *) [ndb_mgmd(MGM)] 2 node(s) id=51 @192.168.1.100 (mysql-5.7.19 ndb-7.5.7) id=52 @192.168.1.101 (mysql-5.7.19 ndb-7.5.7) [mysqld(API)] 4 node(s) id=55 @192.168.1.104 (mysql-5.7.19 ndb-7.5.7) id=56 @192.168.1.105 (mysql-5.7.19 ndb-7.5.7) id=57 (not connected, accepting connect from 192.168.1.104) id=58 (not connected, accepting connect from 192.168.1.105) # here is the error when I try to add memcache plugin to mysql cluster. created ndbmemcache configuration in database, didnt notice any error. # mysql -u root -p ndb_initialize() main --> connect_to_primary_cluster() 27-Oct-2017 15:35:04 UTC NDB Memcache 5.7.19-ndb-7.5.7 started [NDB 7.5.7; MySQL 5.7.19] Contacting primary management server (192.168.1.100:1186,192.168.1.101:1186) ... main --> ClusterConnectionPool::connect() FAILED. Could not connect to NDB. Shutting down. main --> ndb_destroy() Failed to initialize instance. Error code: 255 # cluster management logs ndb_51_cluster.log show this Warning message. 2017-10-27 15:33:44 [MgmtSrvr] WARNING -- Failed to allocate nodeid for API at 192.168.1.104. Returned error: 'No free node id found for mysqld(API).' 2017-10-27 15:35:06 [MgmtSrvr] WARNING -- Failed to allocate nodeid for API at 192.168.1.104. Returned error: 'No free node id found for mysqld(API).' 2017-10-27 15:35:09 [MgmtSrvr] WARNING -- Failed to allocate nodeid for API at 192.168.1.104. Returned error: 'No free node id found for mysqld(API).' 2017-10-27 15:35:12 [MgmtSrvr] WARNING -- Failed to allocate nodeid for API at 192.168.1.104. Returned error: 'No free node id found for mysqld(API).' 2017-10-27 15:35:15 [MgmtSrvr] WARNING -- Failed to allocate nodeid for API at 192.168.1.104. Returned error: 'No free node id found for mysqld(API).' 2017-10-27 15:35:18 [MgmtSrvr] WARNING -- Failed to allocate nodeid for API at 192.168.1.104. Returned error: 'No free node id found for mysqld(API). ' Can someone please suggest how can I fix this issue, I already have additional sql client nodes, but not able to start memcache process. Thanks,

I have two MySQL NDB community clusters 8.0.30, each with 3 VMs Cluster#1_VM1: mysqld + ndb_mgmd Cluster#1_VM2: mysqld + ndb Cluster#1_VM3: mysqld + ndb Cluster#2_VM1: mysqld + ndb_mgmd Cluster#2_VM2: mysqld + ndb Cluster#2_VM3: mysqld + ndb I have bidirectional replication between Cluster#1_VM2 and Cluster#2_VM2. VM2/3 have identical parameters. The choice of such architecture might not be perfect but I think it was not relevant here. mysqld process consumes a lot of memory on VMs with replication. And replication seems to be the only difference between those VMs. (Though I'm not quite sure how is load distributed among mysqld processes) I would assume that ndbd would be the one to use most of the RAM since it has 8GB of DataMemory. But somehow mysqld is also utilizing a lot of RAM too. I've checked several other questions here (e.g. https://dba.stackexchange.com/questions/286946/high-memory-usage-on-replica-mysql-8 ) Most of them are related to innodb and the queries for e.g. buffer utilization show nothing that could show me where that high memory utilization comes from. So far I've checked - buffer utilizations for innoDB (I have NDB, I know) - engine status for innodb and ndb - no hint of high mem usage, or at least not clearly visible All I know for now is that it grows over time after restart of the process. But don't know yet how to limit/control the amount of memory consumed by mysqld in this case.

I am trying to setup mySql manager + data node + sql server (Server A) and another data node cluster on (Server B). Both running on Ubuntu 16.04 amd_64 **Server A** */etc/hosts* also on Server B Both private ip 172.xx.xx.xx ip-172-xx-xx-xx-eu-west-1.compute.internal 172.xx.xx.xx ip-172-xx-xx-xx.eu-east-1.compute.internal */config.ini* [ndbd default] NoOfReplicas=2 # Number of replicas [ndb_mgmd] hostname=ip-172-xx-xx-xx.eu-west-1.compute.internal show Connected to Management Server at: 172.xx.xx.xx:1186 <- A Cluster Configuration --------------------- [ndbd(NDB)] 1 node(s) id=2 (not connected, accepting connect from 172.xx.xx.xx) <- B [ndb_mgmd(MGM)] 1 node(s) id=1 @172.x.x.x (mysql-5.7.22 ndb-7.6.6) [mysqld(API)] 1 node(s) id=3 (not connected, accepting connect from 172.xx.xx.xx) <- A Not sure how would i connect to mysqld(API) that should work fine after i installed the server/client cluster. Also i got inbound on both Instances A & B to accept all traffic between all port ranges 1000-60000 just in case i am missing something, and outbound is open to everything. I wonder what is it i am missing, i got so tired today trying to find out what is going on with the setup. Any help will be appreciated !

I installed a new mysql cluster on windows (for evaluation). I created a table using command below. After I insert just over 1 million records into the table it gives me the "table datadump is full" exception. I have plenty of hard disk space and ram free, and 1 million records is well below the max number of rows for the table. Also the MySql RAm usage has not increased during inserts. I am assuming that MySql has an internal cache limit for the table that was hit. is there a config.ini change I can make to disable caching of rows in cluster table or a modification to the create table script to do the same? create table datadump (name varchar(30) not null) engine=ndb;

My current MySQL NDB Cluster configuration: - Server 1 - management node - Server 2 - huge machine running both ndbd and mysqld - Server 3 - huge machine running both ndbd and mysqld - NoOfReplicas = 1 So server 2 has exact copy of server 3 data During setup evaluation I discovered that mysqld on server 2 is sending about 50% queries to ndbd running on server 3. With greater number of nodes this would be OK to provide load-balancing, but with my specific configuration (both nodes have same dataset) I'd like to get max performance by telling mysqld on each server to PREFER connecting to ndbd process running on localhost, and only connect ndbd on remote host only if local is not available (ie restart) I've read something about server access cost table that should contain information for query optimizer about latency between nodes, but I can't find this blog post right now. Any help?

I am trying to design a multi-master clustered MySQL database which will be spread through out the country. The main reason for having a cluster is so that when the internet, in one location (or node), is disconnected, that location should still be able to read and modify the contents of the database locally. So that when the internet connection is restored, the rest of the cluster get updated. I've went through the MySQL cluster documentation, however, I couldn't find this specific question. Is it possible to achieve this using MySQL cluster?

at this moment I have configured a cluster that has 5 nodes: 2 data nodes 2 SQL nodes 1 node manager My file.config.ini is the following: [ndbd default] NoOfReplicas = 2 # Number of replicas DataMemory = 256M IndexMemory = 100M ServerPort = 2202. MaxNoOfConcurrentTransactions = 429496 MaxNoOfConcurrentOperations = 472496 MaxNoOfLocalOperations = 519745 [ndb_mgmd] NodeId = 1 HostName = 192.168.10.145 # Hostname or IP address of MGM node DataDir = / var / lib / mysql-cluster # Directory for MGM node log files [ndbd] HostName = 192.168.10.181 # Hostname or IP address NodeId = 2 # Node ID for this data node DataDir = / mnt / dataPartition / mysql / data # Directory for this data node's data files [ndbd] HostName = 192.168.10.183 # Hostname or IP address NodeId = 3 # Node ID for this data node DataDir = / mnt / dataPartition / mysql / data # Directory for this data node's data files [mysqld] HostName = 192.168.10.140 # Hostname or IP address # (additional mysqld connections can be # specified for this node for various # purposes such as running ndb_restore) [mysqld] HostName = 192.168.10.184 # Hostname or IP address # (additional mysqld connections can be # specified for this node for various # purposes such as running ndb_restore) [mysqld] IN THE NDB_MGM REPORT, IT SAYS THE FOLLOWING: ndb_mgm> 2 REPORT MEMORYUSAGE Node 2: Data usage is 18% (1476 32K pages of total 8192) Node 2: Index usage is 11% (1461 8K pages of total 12832) ndb_mgm> 3 REPORT MEMORYUSAGE Node 3: Data usage is 18% (1480 32K pages of total 8192) Node 3: Index usage is 11% (1462 8K pages of total 12832) Each data node has 2gb of ram, it is assumed that with this configuration should not consume more than 500 mb of ram the ndbd process, but I am consuming 1.89 gb of ram per node, I am using disk storage for the fields that they are not indexed What is wrong or what is wrong?

I've setup a mysql 8 ndbcluster but cannot get the distributed privileges working. following how to setup distributed privileges using NDB_STORED_USER (https://dev.mysql.com/doc/refman/8.0/en/mysql-cluster-privilege-distribution.html) , i've verified the following: - SHOW ENGINES lists the value of "DEFAULT" for the Support column on the ndbcluster (Engine) row. - Both SQL nodes have "default-storage-engine=ndbcluster" in their my.cnf - I created a user on SQL node 1 and then added them to NDB_STORED_USER.

mysql> GRANT NDB_STORED_USER ON *.* TO 'admin'@'%';
    Query OK, 0 rows affected (0.26 sec)

- I verified I could see the respective GRANTS in ndb_sql_metadata from BOTH SQL Nodes

~$ ndb_select_all -d mysql ndb_sql_metadata
    type	name	seq	note	sql_ddl_text
    11	"'admin'@'%'"	0	2	"CREATE USER 'admin'@'%' IDENTIFIED WITH 'caching_sha2_password' AS '$A$005$MGBmokOj
                                    m! select host, user from mysql.user;
    +-----------+------------------+
    | host      | user             |
    +-----------+------------------+
    | localhost | mysql.infoschema |
    | localhost | mysql.session    |
    | localhost | mysql.sys        |
    | localhost | root             |
    +-----------+------------------+
    4 rows in set (0.00 sec)

Any other suggestions? this is my first time setting up a mysql cluster.

I've setup a ndb cluster with 7 nodes. 3 data nodes on their own servers, and 2 management nodes that each have a sql node on them on 2 servers. I've narrowed down what I think my issue is. My cluster seems to be unable to elect a president data node, but I have no idea how to set the election rules. Can anyone help me with my setup? Is my config wrong? Thanks. Below is all the details. Here is my management node config: [ndbd default] NoOfReplicas=3 #DataMemory=2048M #IndexMemory=512M #Management Nodes [ndb_mgmd] hostname=192.168.0.1 NodeId=1 datadir=/var/lib/mysql-cluster [ndb_mgmd] hostname=192.168.0.2 NodeId=2 datadir=/var/lib/mysql-cluster #Data Nodes [ndbd] hostname=192.168.0.3 NodeId=3 datadir=/usr/local/mysql/data [ndbd] hostname=192.168.0.4 NodeId=4 datadir=/usr/local/mysql/data [ndbd] hostname=192.168.0.5 NodeId=5 datadir=/usr/local/mysql/data #front end servers [mysqld] hostname=192.168.0.1 #NodeId=11 [mysqld] hostname=192.168.0.2 #NodeId=22 Here is my sql node config - my.cnf !includedir /etc/mysql/conf.d/ !includedir /etc/mysql/mysql.conf.d/ [mysqld] ndbcluster [mysql_cluster] ndb-connectstring=192.168.0.1,192.168.0.2 Here is the data node connection string [mysql_cluster] # Options for NDB Cluster processes: ndb-connectstring=192.168.0.1,192.168.0.2 This is what ndb_mgm> show is saying id=3 @192.168.0.3 (mysql-8.3.0 ndb-8.3.0, starting, Nodegroup: 0) id=4 @192.168.0.4 (mysql-8.3.0 ndb-8.3.0, starting, Nodegroup: 0) id=5 @192.168.0.5 (mysql-8.3.0 ndb-8.3.0, starting, Nodegroup: 0) [ndb_mgmd(MGM)] 2 node(s) id=1 @192.168.0.1 (mysql-8.3.0 ndb-8.3.0) id=2 @192.168.0.2 (mysql-8.3.0 ndb-8.3.0) [mysqld(API)] 2 node(s) id=6 (not connected, accepting connect from 192.168.0.1) id=7 (not connected, accepting connect from 192.168.0.2) Nodes 3,4, & 5 are stuck in status ndb_mgm> 3 status Node 3: starting (Last completed phase 0) (mysql-8.3.0 ndb-8.3.0) ndb_mgm> 4 status Node 4: starting (Last completed phase 0) (mysql-8.3.0 ndb-8.3.0) ndb_mgm> 5 status Node 5: starting (Last completed phase 0) (mysql-8.3.0 ndb-8.3.0) SQL Nodes 6 (11) & 7 (22) will not connect. SQL & Data Nodes have nothing in their error logs. The cluster log for the management nodes have this on repeat every minute: TIME [MgmtSrvr] INFO -- Alloc node id 6 rejected, no new president yet TIME [MgmtSrvr] WARNING -- Unable to allocate nodeid for API at 192.168.0.1. Returned error: 'Cluster not ready for nodeid allocation.' TIME [MgmtSrvr] INFO -- Node 3: Initial start, waiting for 4 and 5 to connect, nodes [ all: 3, 4 and 5 connected: 3 no-wait: ] TIME [MgmtSrvr] INFO -- Node 5: Initial start, waiting for 3 and 4 to connect, nodes [ all: 3, 4 and 5 connected: 5 no-wait: ] TIME [MgmtSrvr] INFO -- Node 4: Initial start, waiting for 3 and 5 to connect, nodes [ all: 3, 4 and 5 connected: 4 no-wait: ]

In the official doc https://dev.mysql.com/doc/mysql-replication-excerpt/8.0/en/replication.html It mentioned that if synchronous replication is required, use NDB instead >For scenarios where synchronous replication is required, use NDB Cluster (see MySQL NDB Cluster 7.5 and NDB Cluster 7.6). **Question 1.** Does mysql not support synchronous replication, only mysql cluster support synchronous replication? **Question 2.** Where is the doc for synchronous replciation for NDB I see multiple post mentioning that NDB replication is synchronous by default https://stackoverflow.com/questions/53149674/can-i-implement-synchronous-and-asynchronous-replication-with-the-mysql-cluster But the official doc only mention asynchronous and semisynchronous replication https://dev.mysql.com/doc/refman/8.0/en/mysql-cluster-replication.html > NDB Cluster supports asynchronous replication, more usually referred to simply as “replication”. This section explains how to set up and manage a configuration in which one group of computers operating as an NDB Cluster replicates to a second computer or group of computers. We assume some familiarity on the part of the reader with standard MySQL replication as discussed elsewhere in this Manual. (See Chapter 19, Replication). **Question 3:** If mysql or NDB supports synchronous replication, do they use 2PC? What happens during network partition, or replica nodes are not available? Does NDB sacrifice availability over consistency? Does NDB do leadership election? This post say it does https://dev.mysql.com/blog-archive/2-phase-commit-in-ndbcluster/ But I can't find documentation on the behavior of the trade off on availability vs consistency during network partition or replica failure?

I have configured NDBCLUSTER with 4 data nodes, 1 sql node and 1 management node. But I have increased the 4GB of DataMemory size for every node and IndexMemory size 500MB also. I have given MaxNoOfAttributes=2000 in every node. I have increased the page size for every node. But the problem is I am unable to create more than 110 columns in a table in ndbcluster.

I have a MySQL cluster with 3 Data Nodes and one SQL node. Currently I have 1 million 1kb records. The inserts are very fast, takes only a few ms. But the selects are very slow >20s. All machines are m1.large EC2 instances (8GB RAM). Here is the config.ini: [NDB_MGMD] NodeId=49 HostName=host1 DataDir=/var/lib/mysql-mgmd-data Portnumber=1186 [NDBD DEFAULT] NoOfReplicas=1 DataMemory=1536M IndexMemory=2560M StringMemory=25 MaxNoOfTables=4096 MaxNoOfOrderedIndexes=2048 MaxNoOfUniqueHashIndexes=512 MaxNoOfAttributes=24576 MaxNoOfTriggers=14336 FragmentLogFileSize=256M InitFragmentLogFiles=SPARSE NoOfFragmentLogFiles=16 RedoBuffer=48M MaxNoOfConcurrentOperations=100000 MaxNoOfConcurrentTransactions=16384 TimeBetweenGlobalCheckpoints=1000 TimeBetweenEpochs=100 TimeBetweenEpochsTimeout=32000 DiskCheckpointSpeedInRestart=100M DiskCheckpointSpeed=10M TimeBetweenLocalCheckpoints=20 HeartbeatIntervalDbDb=15000 HeartbeatIntervalDbApi=15000 MemReportFrequency=30 BackupReportFrequency=10 LogLevelStartup=15 LogLevelShutdown=15 LogLevelCheckpoint=8 LogLevelNodeRestart=15 SharedGlobalMemory=384M DiskPageBufferMemory=1G BatchSizePerLocalScan=512 [NDBD] NodeId=1 HostName=host2 DataDir=/mnt/mysql-cluster/1/ [NDBD] NodeId=2 HostName=host3 DataDir=/mnt/mysql-cluster/2/ [NDBD] NodeId=3 HostName=host4 DataDir=/mnt/mysql-cluster/3/ [MYSQLD DEFAULT] [MYSQLD] NodeId=53 HostName=host1 my.cnf [mysqld] ndbcluster ndb-nodeid=53 ndb-connectstring=host1, Insert: INSERT INTO mytab(mykey, a, b, c, d, e, f, g, h, i,j)VALUES (1,1,2,3,4,5,6,7,8,9,0); Select: SELECT * FROM mytab WHERE mykey = 12345; Create table statement: mytab | CREATE TABLE mytab ( mykey varchar(32) NOT NULL, a varchar(100) DEFAULT NULL, b varchar(100) DEFAULT NULL, c varchar(100) DEFAULT NULL, d varchar(100) DEFAULT NULL, e varchar(100) DEFAULT NULL, f varchar(100) DEFAULT NULL, g varchar(100) DEFAULT NULL, h varchar(100) DEFAULT NULL, i varchar(100) DEFAULT NULL, j varchar(100) DEFAULT NULL, PRIMARY KEY (mykey) ) /*!50100 TABLESPACE mytab_space STORAGE DISK */ ENGINE=ndbcluster DEFAULT CHARSET=latin1 MAX_ROWS=1000000000 /*!50100 PARTITION BY KEY (mykey) */ | Has someone an idea why it is so slow? Has someone experience with MySQL-cluster and EC2 m1.large instances?

I'm trying to execute ndb_desc from API client. The config and parameters are as below: my.cnf in mysqld: [mysql_cluster] ndb-connectstring=192.168.1.1,192.168.1.2 server-id=5 log-bin=mysql-bin config.ini in mgmd: (part of it) -- ... [mysqld] hostname=192.168.1.5 --- ... Situation: there are 2x mgmd, 2x data-node, and 2x mysqld. Parameters tried to call ndb_desc: # ndb_desc -c 192.168.1.1 --ndb-nodeid=7 -d db_name -t tb_name Above response with error: ndb_desc: [ERROR] unknown variable 'server-id=5 On changing my.cnf, removing these two lines of server-id and log-bin, then the error response after calling ndb_desc will be as follow: Unable to connect to management server. NDBT_ProgramExit: 1 - Failed There is no firewall, ping to the management is running fine. So the question: how to exec ndb_desc (with correct parameters)? what is the correct my.cnf/config.ini for setting up the node-id? Some links i have tried to check before posting this: mysql-cluster-work-well-but-ndb-desc-doesnt-work , mysql:ndb_desc , mysql:connection-string , grokbase , and several hours of googling around. update1: changed the config.ini on mgmd for emtpy mysqld section, ndb_mgm -e show output: [mysqld(API)] 3 node(s) id=5 @192.168.1.5 (mysql-5.7.23 ndb-7.6.7) id=6 @192.168.1.6 (mysql-5.7.23 ndb-7.6.7) id=7 (not connected, accepting connect from any host) ndb_desc still has the same response: Unable to connect to management server. update2: from mgmd node, saw this log: WARNING -- Failed to allocate nodeid for API at 192.168.1.5. Returned error: 'Id 7 already allocated by another node. update3: changed config.ini, added [api] nodeid=7 host=192.168.1.5. log still the same: WARNING -- Failed to allocate nodeid for API at 192.168.11.51. Returned error: 'No free node id found for mysqld(API).

I tried to set up a MySQL cluster and failed. I finally got it switched back to standard MySQL, but now I have an ndbinfo database that I cannot drop. It causes my automysqlbackup cron job to report errors.

mysql> drop database ndbinfo;
ERROR 1286 (42000): Unknown storage engine 'ndbinfo'

Is there any way to manually remove the database? Or maybe a procedure that I do not know about? I did not see 'ndbinfo' referenced anywhere in the MySQL database. It's on Ubuntu Server 22.04 from the MySQL APT repository. Output from mysql --version:

mysql  Ver 8.0.33 for Linux on x86_64 (MySQL Community Server - GPL)

I have three server that I want to Install Galera clustering on them, I followed this [link](https://www.digitalocean.com/community/tutorials/how-to-configure-a-galera-cluster-with-mariadb-on-ubuntu-12-04-servers) to install and config it. but when I want to start the first server I got this error : root@node107:/home/debian# service mysql start --wsrep-new-clusterping Job for mysql.service failed. See 'systemctl status mysql.service' and 'journalctl -xn' for details. and : root@node107:/home/debian# journalctl -xn -- Logs begin at Tue 2016-03-01 19:02:04 IRST, end at Tue 2016-03-01 19:39:32 IRST. -- Mar 01 19:39:31 node107 mysqld: 160301 19:39:31 [ERROR] WSREP: gcs/src/gcs.cpp:gcs_open():1379: Failed to open channel 'test_cluster' at 'gcomm://192.168.120.107,192.168.120.111,192.168.120.11 Mar 01 19:39:31 node107 mysqld: 160301 19:39:31 [ERROR] WSREP: gcs connect failed: Connection timed out Mar 01 19:39:31 node107 mysqld: 160301 19:39:31 [ERROR] WSREP: wsrep::connect(gcomm://192.168.120.107,192.168.120.111,192.168.120.117) failed: 7 Mar 01 19:39:31 node107 mysqld: 160301 19:39:31 [ERROR] Aborting Mar 01 19:39:31 node107 mysqld: Mar 01 19:39:31 node107 mysqld: 160301 19:39:31 [Note] WSREP: Service disconnected. Mar 01 19:39:32 node107 mysqld: 160301 19:39:32 [Note] WSREP: Some threads may fail to exit. Mar 01 19:39:32 node107 mysqld: 160301 19:39:32 [Note] /usr/sbin/mysqld: Shutdown complete Mar 01 19:39:32 node107 mysqld: Mar 01 19:39:32 node107 mysqld_safe: mysqld from pid file /var/run/mysqld/mysqld.pid ended these are configuration file for the three servers : vim /etc/mysql/conf.d/cluster.cnf **Server1 :** [mysqld] query_cache_size=0 binlog_format=ROW default-storage-engine=innodb innodb_autoinc_lock_mode=2 query_cache_type=0 bind-address=0.0.0.0 # Galera Provider Configuration wsrep_provider=/usr/lib/galera/libgalera_smm.so #wsrep_provider_options="gcache.size=32G" # Galera Cluster Configuration wsrep_cluster_name="test_cluster" wsrep_cluster_address="gcomm://192.168.120.107,192.168.120.111,192.168.120.117" #wsrep_cluster_address="gcomm://192.168.120.107" # Galera Synchronization Congifuration wsrep_sst_method=rsync #wsrep_sst_auth=user:pass # Galera Node Configuration wsrep_node_address="192.168.120.107" wsrep_node_name="node107" **Server 2:** [mysqld] query_cache_size=0 binlog_format=ROW default-storage-engine=innodb innodb_autoinc_lock_mode=2 query_cache_type=0 bind-address=0.0.0.0 # Galera Provider Configuration wsrep_provider=/usr/lib/galera/libgalera_smm.so #wsrep_provider_options="gcache.size=32G" # Galera Cluster Configuration wsrep_cluster_name="test_cluster" wsrep_cluster_address="gcomm://192.168.120.107" #wsrep_cluster_address="gcomm://192.168.120.107,192.168.120.111,192.168.120.117" # Galera Synchronization Congifuration wsrep_sst_method=rsync #wsrep_sst_auth=user:pass # Galera Node Configuration wsrep_node_address="192.168.120.111" wsrep_node_name="node111" **server 3 :** [mysqld] query_cache_size=0 binlog_format=ROW default-storage-engine=innodb innodb_autoinc_lock_mode=2 query_cache_type=0 bind-address=0.0.0.0 # Galera Provider Configuration wsrep_provider=/usr/lib/galera/libgalera_smm.so #wsrep_provider_options="gcache.size=32G" # Galera Cluster Configuration wsrep_cluster_name="test_cluster" wsrep_cluster_address="gcomm://192.168.120.107,192.168.120.111,192.168.120.117" # Galera Synchronization Congifuration wsrep_sst_method=rsync #wsrep_sst_auth=user:pass # Galera Node Configuration wsrep_node_address="192.168.120.117" wsrep_node_name="node117" I don't understand what I have missed. what should I do?

According to the limitations outlined at http://dev.mysql.com/doc/refman/5.7/en/mysql-cluster-limitations.html , there can only be 48 data nodes. Does that mean, with number of replicas 2, I can actually have only 24 nodes to store data? If the data memory is, say 4GB, then, does it mean I can only store 24*4=~100GB? If so, how can I set up a cluster to store TBs of data?

When using the MySQL NDB Cluster distributed database, the following general problem has arisen: To insert a new Record / Row, the last row in the database should be read, see if it is compatible with the row to be inserted and then insert the new row. However, the problem arises that in the meantime another instance also runs through the same process and then at the end both new rows have checked to the same last record to be compatible and are inserted. Is there a way to block this with a locking process? So that one instance gets the last row/ record via JDBC in Java and locks this row for reading, then checks the object and then insert the new record and now a second instance can run through the same process? Thanks for your answers.

I know that with NDB you can not do large transactions, if you do data nodes can restart into read-only mode and corrupt table. I need to copy records into a new table but the thing is this table contains millions of rows in staging, the live server has even 10 times that amount. how can I divide my copy into smaller transactions so I will not kill my server?