problems with node joining the cluster when using sst:xtrabackup (galera)

Question 1

problems with node joining the cluster when using sst:xtrabackup (galera)

load-balancing mariadb galera

nimesh · Dec 4, 2013 · Viewed 16.5k times · Source

Answer

Answer

The problem was that there was a directory of database backups (dbexport) in MariaDB's data directory (probably /var/lib/mysql/). When doing the SST, the provider scans the data directory to find the files to send. It saw the directory and assumed that it was for a database since that's what the directories in the data directory are for. Removing the backup directory fixed the problem. As a best practice, don't change anything in /var/lib/; programs usually keep their data files in there and messing with them can cause problems like this.

After the main problem was resolved, a new message was noticed in the logs:

[Warning] WSREP: Failed to prepare for incremental state transfer: Local state UUID (00000000-0000-0000-0000-000000000000) does not match group state UUID (359350ee-5c63-11e3-0800-6673d15135cd): 1 (Operation not permitted) at galera/src/replicator_str.cpp:prepare_for_IST():442. IST will be unavailable.

This message is normal. When a node joins a galera cluster it will try to perform an IST (Incremental State Transfer) instead of the full SST (State Snapshot Transfer). If the node was previously part of the cluster and the difference between the state it had when it left and the current state of the cluster is small enough, IST is available which just transfers the differences between the node's current state and the cluster's state. This is much faster than transferring all of the data. If the node was previously part of the cluster but left long time ago, it will need to do an SST. In this case the, joining node's state UUID was 00000000-0000-0000-0000-000000000000 which basically means it is new to the cluster. I run a MariaDB/galera cluster and this message annoys me whenever IST is not available. It would be nice if it wasn't a warning and was reworded. I'm not sure why Operation not permitted is in there, but it's nothing to worry about.

Additionally, it is recommended that you run an odd number of nodes to prevent split brain conditions. If possible, you should add another MariaDB server to the cluster or run garbd if you cannot. garbd acts as a node in the cluster without being a database server. It allows you to have an odd number of nodes without needed to have another database server.

Question 2

It looks like the node is joining the cluster and then it fails… I have tried with both rsync and xtrabackup and it fails during state transfer. I seems to me that I am missing something real simple and I am not able to put a finger on it.. Any help would be appreciated.

More information regarding the nodes

Master - 10.XXX.XXX.161 node1 - 10.XXX.XXX.160

Packages installed: MariaDB-compat MariaDB-common MariaDB-devel MariaDB-shared MariaDB-client MariaDB-test MariaDB-Galera-server (v5.5.29-1) galera (v23.2.4-1.rhel6) percona-xtrabackup (v2.1.6-702.rhel6)

config for node 1

[mysqld]
wsrep_cluster_address = gcomm://10.XXX.XXX.161
wsrep_provider = /usr/lib64/galera/libgalera_smm.so
wsrep_provider_options = gcache.size=4G; gcache.page_size=1G
wsrep_cluster_name = galera_cluster
default_storage_engine = InnoDB
innodb_autoinc_lock_mode = 2
innodb_locks_unsafe_for_binlog = 1
wsrep_sst_method = xtrabackup
wsrep_sst_auth = root:rootpassword
wsrep_node_name=1

config for master

[mysqld]
wsrep_cluster_address = gcomm://
wsrep_provider = /usr/lib64/galera/libgalera_smm.so
wsrep_provider_options = gcache.size=4G; gcache.page_size=1G
wsrep_cluster_name = galera_cluster
default_storage_engine = InnoDB
innodb_autoinc_lock_mode = 2
innodb_locks_unsafe_for_binlog = 1
wsrep_sst_method = rsync
wsrep_slave_threads = 4
wsrep_sst_auth = root:rootpassword
wsrep_node_name = 2

node1 log file

131203 16:09:03 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
131203 16:09:03 mysqld_safe WSREP: Running position recovery with --log_error=/tmp/tmp.f2EedjRjbQ
131203 16:09:08 mysqld_safe WSREP: Recovered position 359350ee-5c63-11e3-0800-6673d15135cd:2188
131203 16:09:08 [Note] WSREP: wsrep_start_position var submitted: '359350ee-5c63-11e3-0800-6673d15135cd:2188'
131203 16:09:08 [Note] WSREP: Read nil XID from storage engines, skipping position init
131203 16:09:08 [Note] WSREP: wsrep_load(): loading provider library '/usr/lib64/galera/libgalera_smm.so'
131203 16:09:08 [Note] WSREP: wsrep_load(): Galera 23.2.4(r147) by Codership Oy <[email protected]]]> loaded succesfully.
131203 16:09:08 [Note] WSREP: Found saved state: 00000000-0000-0000-0000-000000000000:-1
131203 16:09:08 [Note] WSREP: Reusing existing '/var/lib/mysql//galera.cache'.
131203 16:09:08 [Note] WSREP: Passing config to GCS: base_host = 10.XXX.XXX.160; base_port = 4567; cert.log_conflicts = no; gcache.dir = /var/lib/mysql/; gcache.keep_pages_size = 0; gcache.mem_size = 0; gcache.name = /var/lib/mysql//galera.cache; gcache.page_size = 1G; gcache.size = 4G; gcs.fc_debug = 0; gcs.fc_factor = 1; gcs.fc_limit = 16; gcs.fc_master_slave = NO; gcs.max_packet_size = 64500; gcs.max_throttle = 0.25; gcs.recv_q_hard_limit = 9223372036854775807; gcs.recv_q_soft_limit = 0.25; gcs.sync_donor = NO; replicator.causal_read_timeout = PT30S; replicator.commit_order = 3
131203 16:09:08 [Note] WSREP: Assign initial position for certification: -1, protocol version: -1
131203 16:09:08 [Note] WSREP: wsrep_sst_grab()
131203 16:09:08 [Note] WSREP: Start replication
131203 16:09:08 [Note] WSREP: Setting initial position to 00000000-0000-0000-0000-000000000000:-1
131203 16:09:08 [Note] WSREP: protonet asio version 0
131203 16:09:08 [Note] WSREP: backend: asio
131203 16:09:08 [Note] WSREP: GMCast version 0
131203 16:09:08 [Note] WSREP: (8814b4ba-5c67-11e3-0800-91035d554a96, 'tcp://0.0.0.0:4567') listening at tcp://0.0.0.0:4567
131203 16:09:08 [Note] WSREP: (8814b4ba-5c67-11e3-0800-91035d554a96, 'tcp://0.0.0.0:4567') multicast: , ttl: 1
131203 16:09:08 [Note] WSREP: EVS version 0
131203 16:09:08 [Note] WSREP: PC version 0
131203 16:09:08 [Note] WSREP: gcomm: connecting to group 'galera_cluster', peer '10.XXX.XXX.161:'
131203 16:09:09 [Note] WSREP: declaring 7a9a87e8-5c67-11e3-0800-8cb6cba8f65a stable
131203 16:09:09 [Note] WSREP: Node 7a9a87e8-5c67-11e3-0800-8cb6cba8f65a state prim
131203 16:09:09 [Note] WSREP: view(view_id(PRIM,7a9a87e8-5c67-11e3-0800-8cb6cba8f65a,2) memb {
     7a9a87e8-5c67-11e3-0800-8cb6cba8f65a,
     8814b4ba-5c67-11e3-0800-91035d554a96,
} joined {
} left {
} partitioned {
})
131203 16:09:09 [Note] WSREP: gcomm: connected
131203 16:09:09 [Note] WSREP: Changing maximum packet size to 64500, resulting msg size: 32636
131203 16:09:09 [Note] WSREP: Shifting CLOSED -> OPEN (TO: 0)
131203 16:09:09 [Note] WSREP: Opened channel 'galera_cluster'
131203 16:09:09 [Note] WSREP: New COMPONENT: primary = yes, bootstrap = no, my_idx = 1, memb_num = 2
131203 16:09:09 [Note] WSREP: STATE EXCHANGE: Waiting for state UUID.
131203 16:09:09 [Note] WSREP: Waiting for SST to complete.
131203 16:09:09 [Note] WSREP: STATE EXCHANGE: sent state msg: 8861cdd5-5c67-11e3-0800-cc70fcc5f515
131203 16:09:09 [Note] WSREP: STATE EXCHANGE: got state msg: 8861cdd5-5c67-11e3-0800-cc70fcc5f515 from 0 (2)
131203 16:09:09 [Note] WSREP: STATE EXCHANGE: got state msg: 8861cdd5-5c67-11e3-0800-cc70fcc5f515 from 1 (1)
131203 16:09:09 [Note] WSREP: Quorum results:
     version    = 2,
     component  = PRIMARY,
     conf_id    = 1,
     members    = 1/2 (joined/total),
     act_id     = 2521,
     last_appl. = -1,
     protocols  = 0/4/2 (gcs/repl/appl),
     group UUID = 359350ee-5c63-11e3-0800-6673d15135cd
131203 16:09:09 [Note] WSREP: Flow-control interval: [23, 23]
131203 16:09:09 [Note] WSREP: Shifting OPEN -> PRIMARY (TO: 2521)
131203 16:09:09 [Note] WSREP: State transfer required:
     Group state: 359350ee-5c63-11e3-0800-6673d15135cd:2521
     Local state: 00000000-0000-0000-0000-000000000000:-1
131203 16:09:09 [Note] WSREP: New cluster view: global state: 359350ee-5c63-11e3-0800-6673d15135cd:2521, view# 2: Primary, number of nodes: 2, my index: 1, protocol version 2
131203 16:09:09 [Warning] WSREP: Gap in state sequence. Need state transfer.
131203 16:09:11 [Note] WSREP: Running: 'wsrep_sst_xtrabackup --role 'joiner' --address '10.XXX.XXX.160' --auth 'root:rootpassword' --datadir '/var/lib/mysql/' --defaults-file '/etc/my.cnf' --parent '13175''
131203 16:09:11 [Note] WSREP: Prepared SST request: xtrabackup|10.162.143.160:4444/xtrabackup_sst
131203 16:09:11 [Note] WSREP: wsrep_notify_cmd is not defined, skipping notification.
131203 16:09:11 [Note] WSREP: Assign initial position for certification: 2521, protocol version: 2
131203 16:09:11 [Warning] WSREP: Failed to prepare for incremental state transfer: Local state UUID (00000000-0000-0000-0000-000000000000) does not match group state UUID (359350ee-5c63-11e3-0800-6673d15135cd): 1 (Operation not permitted)
      at galera/src/replicator_str.cpp:prepare_for_IST():442. IST will be unavailable.
131203 16:09:11 [Note] WSREP: Node 1 (1) requested state transfer from '*any*'. Selected 0 (2)(SYNCED) as donor.
131203 16:09:11 [Note] WSREP: Shifting PRIMARY -> JOINER (TO: 2525)
131203 16:09:11 [Note] WSREP: Requesting state transfer: success, donor: 0
tar: dbexport/db.opt: Cannot open: Permission denied
tar: Exiting with failure status due to previous errors
131203 16:10:22 [Note] WSREP: 0 (2): State transfer to 1 (1) complete.
131203 16:10:22 [Note] WSREP: Member 0 (2) synced with group.
WSREP_SST: [ERROR] Error while getting st data from donor node:  0, 2 (20131203 16:10:22.379)
131203 16:10:22 [ERROR] WSREP: Process completed with error: wsrep_sst_xtrabackup --role 'joiner' --address '10.XXX.XXX.160' --auth 'root:rootpassword' --datadir '/var/lib/mysql/' --defaults-file '/etc/my.cnf' --parent '13175': 32 (Broken pipe)
131203 16:10:22 [ERROR] WSREP: Failed to read uuid:seqno from joiner script.
131203 16:10:22 [ERROR] WSREP: SST failed: 32 (Broken pipe)
131203 16:10:22 [ERROR] Aborting
131203 16:10:24 [Note] WSREP: Closing send monitor...
131203 16:10:24 [Note] WSREP: Closed send monitor.
131203 16:10:24 [Note] WSREP: gcomm: terminating thread
131203 16:10:24 [Note] WSREP: gcomm: joining thread
131203 16:10:24 [Note] WSREP: gcomm: closing backend
131203 16:10:25 [Note] WSREP: view(view_id(NON_PRIM,7a9a87e8-5c67-11e3-0800-8cb6cba8f65a,2) memb {
     8814b4ba-5c67-11e3-0800-91035d554a96,
} joined {
} left {
} partitioned {
     7a9a87e8-5c67-11e3-0800-8cb6cba8f65a,
})
131203 16:10:25 [Note] WSREP: view((empty))
131203 16:10:25 [Note] WSREP: gcomm: closed
131203 16:10:25 [Note] WSREP: New COMPONENT: primary = no, bootstrap = no, my_idx = 0, memb_num = 1
131203 16:10:25 [Note] WSREP: Flow-control interval: [16, 16]
131203 16:10:25 [Note] WSREP: Received NON-PRIMARY.
131203 16:10:25 [Note] WSREP: Shifting JOINER -> OPEN (TO: 2607)
131203 16:10:25 [Note] WSREP: Received self-leave message.
131203 16:10:25 [Note] WSREP: Flow-control interval: [0, 0]
131203 16:10:25 [Note] WSREP: Received SELF-LEAVE. Closing connection.
131203 16:10:25 [Note] WSREP: Shifting OPEN -> CLOSED (TO: 2607)
131203 16:10:25 [Note] WSREP: RECV thread exiting 0: Success
131203 16:10:25 [Note] WSREP: recv_thread() joined.
131203 16:10:25 [Note] WSREP: Closing slave action queue.
131203 16:10:25 [Note] WSREP: Service disconnected.
131203 16:10:25 [Note] WSREP: rollbacker thread exiting
131203 16:10:26 [Note] WSREP: Some threads may fail to exit.
131203 16:10:26 [Note] /usr/sbin/mysqld: Shutdown complete
Error in my_thread_global_end(): 2 threads didn't exit
131203 16:10:31 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended

master log file

131203 16:08:47 [Warning] Recovery from master pos 103358630 and file mysql-bin.000131.
131203 16:08:47 [Note] Event Scheduler: Loaded 0 events
131203 16:08:47 [Note] WSREP: wsrep_notify_cmd is not defined, skipping notification.
131203 16:08:47 [Note] WSREP: Assign initial position for certification: 2497, protocol version: 2
131203 16:08:47 [Note] /usr/sbin/mysqld: ready for connections.
Version: '5.5.29-MariaDB-log'  socket: '/var/lib/mysql/mysql.sock'  port: 3306  MariaDB Server, wsrep_23.7.3.rXXXX
131203 16:08:47 [Note] WSREP: Synchronized with group, ready for connections
131203 16:08:47 [Note] WSREP: wsrep_notify_cmd is not defined, skipping notification.
131203 16:09:09 [Note] WSREP: declaring 8814b4ba-5c67-11e3-0800-91035d554a96 stable
131203 16:09:09 [Note] WSREP: Node 7a9a87e8-5c67-11e3-0800-8cb6cba8f65a state prim
131203 16:09:09 [Note] WSREP: view(view_id(PRIM,7a9a87e8-5c67-11e3-0800-8cb6cba8f65a,2) memb {
     7a9a87e8-5c67-11e3-0800-8cb6cba8f65a,
     8814b4ba-5c67-11e3-0800-91035d554a96,
} joined {
} left {
} partitioned {
})
131203 16:09:09 [Note] WSREP: New COMPONENT: primary = yes, bootstrap = no, my_idx = 0, memb_num = 2
131203 16:09:09 [Note] WSREP: STATE_EXCHANGE: sent state UUID: 8861cdd5-5c67-11e3-0800-cc70fcc5f515
131203 16:09:09 [Note] WSREP: STATE EXCHANGE: sent state msg: 8861cdd5-5c67-11e3-0800-cc70fcc5f515
131203 16:09:09 [Note] WSREP: STATE EXCHANGE: got state msg: 8861cdd5-5c67-11e3-0800-cc70fcc5f515 from 0 (2)
131203 16:09:09 [Note] WSREP: STATE EXCHANGE: got state msg: 8861cdd5-5c67-11e3-0800-cc70fcc5f515 from 1 (1)
131203 16:09:09 [Note] WSREP: Quorum results:
     version    = 2,
     component  = PRIMARY,
     conf_id    = 1,
     members    = 1/2 (joined/total),
     act_id     = 2521,
     last_appl. = 2517,
     protocols  = 0/4/2 (gcs/repl/appl),
     group UUID = 359350ee-5c63-11e3-0800-6673d15135cd
131203 16:09:09 [Note] WSREP: Flow-control interval: [23, 23]
131203 16:09:09 [Note] WSREP: New cluster view: global state: 359350ee-5c63-11e3-0800-6673d15135cd:2521, view# 2: Primary, number of nodes: 2, my index: 0, protocol version 2
131203 16:09:09 [Note] WSREP: wsrep_notify_cmd is not defined, skipping notification.
131203 16:09:09 [Note] WSREP: Assign initial position for certification: 2521, protocol version: 2
131203 16:09:11 [Note] WSREP: Node 1 (1) requested state transfer from '*any*'. Selected 0 (2)(SYNCED) as donor.
131203 16:09:11 [Note] WSREP: Shifting SYNCED -> DONOR/DESYNCED (TO: 2525)
131203 16:09:11 [Note] WSREP: wsrep_notify_cmd is not defined, skipping notification.
131203 16:09:11 [Note] WSREP: Running: 'wsrep_sst_xtrabackup --role 'donor' --address '10.XXX.XXX.160:4444/xtrabackup_sst' --auth 'root:rootpassword' --socket '/var/lib/mysql/mysql.sock' --datadir '/var/lib/mysql/' --defaults-file '/etc/my.cnf' --gtid '359350ee-5c63-11e3-0800-6673d15135cd:2525''
131203 16:09:11 [Note] WSREP: sst_donor_thread signaled with 0
131203 16:10:20 [Note] WSREP: Provider paused at 359350ee-5c63-11e3-0800-6673d15135cd:2604
131203 16:10:22 [Note] WSREP: Provider resumed.
131203 16:10:22 [Note] WSREP: 0 (2): State transfer to 1 (1) complete.
131203 16:10:22 [Note] WSREP: Shifting DONOR/DESYNCED -> JOINED (TO: 2606)
131203 16:10:22 [Note] WSREP: Member 0 (2) synced with group.
131203 16:10:22 [Note] WSREP: Shifting JOINED -> SYNCED (TO: 2606)
131203 16:10:22 [Note] WSREP: Synchronized with group, ready for connections
131203 16:10:22 [Note] WSREP: wsrep_notify_cmd is not defined, skipping notification.
131203 16:10:25 [Note] WSREP: Node 7a9a87e8-5c67-11e3-0800-8cb6cba8f65a state prim
131203 16:10:25 [Note] WSREP: view(view_id(PRIM,7a9a87e8-5c67-11e3-0800-8cb6cba8f65a,3) memb {
     7a9a87e8-5c67-11e3-0800-8cb6cba8f65a,
} joined {
} left {
} partitioned {
     8814b4ba-5c67-11e3-0800-91035d554a96,
})
131203 16:10:25 [Note] WSREP: forgetting 8814b4ba-5c67-11e3-0800-91035d554a96 (tcp://10.XXX.XXX.160:4567)
131203 16:10:25 [Note] WSREP: New COMPONENT: primary = yes, bootstrap = no, my_idx = 0, memb_num = 1
131203 16:10:25 [Note] WSREP: STATE_EXCHANGE: sent state UUID: b5dda52e-5c67-11e3-0800-4b2360dd84f9
131203 16:10:25 [Note] WSREP: STATE EXCHANGE: sent state msg: b5dda52e-5c67-11e3-0800-4b2360dd84f9
131203 16:10:25 [Note] WSREP: STATE EXCHANGE: got state msg: b5dda52e-5c67-11e3-0800-4b2360dd84f9 from 0 (2)
131203 16:10:25 [Note] WSREP: Quorum results:
     version    = 2,
     component  = PRIMARY,
     conf_id    = 2,
     members    = 1/1 (joined/total),
     act_id     = 2607,
     last_appl. = 2597,
     protocols  = 0/4/2 (gcs/repl/appl),
     group UUID = 359350ee-5c63-11e3-0800-6673d15135cd
131203 16:10:25 [Note] WSREP: Flow-control interval: [16, 16]
131203 16:10:25 [Note] WSREP: New cluster view: global state: 359350ee-5c63-11e3-0800-6673d15135cd:2607, view# 3: Primary, number of nodes: 1, my index: 0, protocol version 2
131203 16:10:25 [Note] WSREP: wsrep_notify_cmd is not defined, skipping notification.
131203 16:10:25 [Note] WSREP: Assign initial position for certification: 2607, protocol version: 2
131203 16:10:30 [Note] WSREP:  cleaning up 8814b4ba-5c67-11e3-0800-91035d554a96 (tcp://10..XXX.XXX.160:4567)

problems with node joining the cluster when using sst:xtrabackup (galera)

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