Lock wait timeout and other errors (no replies)

Hello. I'm trying to use MySQL Cluster, but sometimes queries take long time and i get error "lock wait timeout exceeded".

There are following strings in logs:

2015-02-13 23:41:40 27483 [Note] NDB Binlog: Node: 1, down, Subscriber bitmask 00
2015-02-13 23:41:40 27483 [Note] NDB Binlog: Node: 2, down, Subscriber bitmask 00
2015-02-13 23:41:40 27483 [Note] NDB Binlog: cluster failure for ./mysql/ndb_schema at epoch 24339/0.
2015-02-13 23:41:40 27483 [Note] NDB Binlog: cluster failure for ./mysql/ndb_apply_status at epoch 24339/0.
2015-02-13 23:41:40 27483 [Note] Restarting Cluster Binlog
2015-02-13 23:41:40 27483 [Note] NDB Binlog: Ndb object created with reference : 0x80030035, name : Ndb Binlog schema change monitoring
2015-02-13 23:41:40 27483 [Note] NDB Binlog: Ndb object created with reference : 0x80050035, name : Ndb Binlog data change monitoring
2015-02-13 23:41:40 27483 [Note] NDB Binlog: DISCOVER TABLE Event: REPL$mysql/ndb_schema
2015-02-13 23:41:40 27483 [ERROR] NDB Binlog: Creating NdbEventOperation failed for REPL$mysql/ndb_schema
2015-02-13 23:41:40 27483 [ERROR] NDB Binlog:FAILED CREATE (DISCOVER) EVENT OPERATIONS Event: REPL$mysql/ndb_schema
2015-02-13 23:41:41 27483 [Note] table './lsd_test/t_events' opened read only
2015-02-13 23:41:41 27483 [Note] NDB Binlog: DISCOVER TABLE Event: REPL$mysql/ndb_schema
2015-02-13 23:41:41 27483 [ERROR] NDB Binlog: Creating NdbEventOperation failed for REPL$mysql/ndb_schema
2015-02-13 23:41:41 27483 [ERROR] NDB Binlog:FAILED CREATE (DISCOVER) EVENT OPERATIONS Event: REPL$mysql/ndb_schema
2015-02-13 23:41:41 27483 [Note] table './lsd_test/t_messages' opened read only


(every table opened read only, so i didn't include all those strings)

2015-02-13 23:41:41 27483 [Note] table './lsd_test/t_event_members' opened read only
2015-02-13 23:41:42 27483 [Note] NDB Binlog: DISCOVER TABLE Event: REPL$mysql/ndb_schema
2015-02-13 23:41:42 27483 [ERROR] NDB Binlog: Creating NdbEventOperation failed for REPL$mysql/ndb_schema
2015-02-13 23:41:42 27483 [ERROR] NDB Binlog:FAILED CREATE (DISCOVER) EVENT OPERATIONS Event: REPL$mysql/ndb_schema
2015-02-13 23:41:43 27483 [Note] NDB Binlog: DISCOVER TABLE Event: REPL$mysql/ndb_schema
2015-02-13 23:41:43 27483 [ERROR] NDB Binlog: Creating NdbEventOperation failed for REPL$mysql/ndb_schema
2015-02-13 23:41:43 27483 [ERROR] NDB Binlog:FAILED CREATE (DISCOVER) EVENT OPERATIONS Event: REPL$mysql/ndb_schema
2015-02-13 23:41:44 27483 [Note] table './lsd_test/t_relations' opened read only
2015-02-13 23:41:44 27483 [Note] NDB Binlog: DISCOVER TABLE Event: REPL$mysql/ndb_schema
2015-02-13 23:42:11 27483 [Note] table './lsd_test/t_event_members' opened read only
2015-02-13 23:42:14 27483 [Note] NDB Binlog: logging ./mysql/ndb_schema (UPDATED,USE_WRITE)
2015-02-13 23:42:14 27483 [Note] NDB Binlog: DISCOVER TABLE Event: REPL$mysql/ndb_apply_status
2015-02-13 23:42:14 27483 [Note] table './lsd_test/t_relations' opened read only
2015-02-13 23:42:14 27483 [Note] NDB Binlog: logging ./mysql/ndb_apply_status (UPDATED,USE_WRITE)
2015-02-13 23:42:14 27483 [Note] NDB: Cleaning stray tables from database 'information_schema'
2015-02-13 23:42:14 27483 [Note] NDB: Cleaning stray tables from database 'lsd_test'
2015-02-13 23:42:14 27483 [Note] NDB: Cleaning stray tables from database 'lsd_test_innodb'
2015-02-13 23:42:14 27483 [Note] NDB: Cleaning stray tables from database 'mytest'
2015-02-13 23:42:14 27483 [Note] NDB: Cleaning stray tables from database 'ndbinfo'
2015-02-13 23:42:14 27483 [Note] NDB: Cleaning stray tables from database 'performance_schema'
2015-02-13 23:42:14 27483 [Note] NDB: Cleaning stray tables from database 'test'
2015-02-13 23:42:14 27483 [Note] NDB: Cleaning stray tables from database 'test1'
2015-02-13 23:42:14 27483 [Note] NDB: Cleaning stray tables from database 'test_ndb'
2015-02-13 23:42:14 [NdbApi] INFO -- Flushing incomplete GCI:s < 24372/9
2015-02-13 23:42:14 [NdbApi] INFO -- Flushing incomplete GCI:s < 24372/9
2015-02-13 23:42:14 27483 [Note] NDB Binlog: starting log at epoch 24372/9
2015-02-13 23:42:14 27483 [Note] NDB Binlog: ndb tables writable



I have following settings in config.ini:
TransactionDeadlockDetectionTimeout=52000 #default 1200
MaxNoOfConcurrentTransactions=16384
MaxNoOfConcurrentOperations=100000

BatchSizePerLocalScan=512
FragmentLogFileSize=256M
NoOfFragmentLogFiles=22 # 6xDataMemory [in MB]/(4 *FragmentLogFileSize [in MB])

RedoBuffer=48M
MaxNoOfExecutionThreads=4
StopOnError=false
LockPagesInMainMemory=1

#severalnines settings
TransactionBufferMemory=8M

TimeBetweenGlobalCheckpoints=1000
TimeBetweenEpochs=100

TimeBetweenEpochsTimeout=0
DiskCheckpointSpeedInRestart=100M
DiskCheckpointSpeed=10M
TimeBetweenLocalCheckpoints=20

### Heartbeating
HeartbeatIntervalDbDb=15000
HeartbeatIntervalDbApi=15000

### Params for setting logging
MemReportFrequency=30
BackupReportFrequency=10
LogLevelStartup=15
LogLevelShutdown=15
LogLevelCheckpoint=8
LogLevelNodeRestart=15

### Params for BACKUP
BackupMaxWriteSize=1M
BackupDataBufferSize=24M
BackupLogBufferSize=16M
BackupMemory=40M

TimeBetweenWatchdogCheckInitial=60000
TransactionInactiveTimeout=800
RedoOverCommitCounter=3
RedoOverCommitLimit=20
NoOfFragmentLogParts=4

### Increasing the LongMessageBuffer b/c of a bug (20090903)
LongMessageBuffer=16M


I reset TransactionInactiveTimeout to 800 from severalnines config and TransactionDeadlockDetectionTimeout to 52000 from default.

Also there is my.cnf parameters:
#severalnines
ndbcluster=1
ndb-connectstring="192.168.1.5:1186,192.168.1.6:1186"
ndb-force-send=1
ndb-use-exact-count=0
ndb-extra-logging=1
ndb-batch-size=24M
ndb-autoincrement-prefetch-sz=1024
#OTHER THINGS, BUFFERS ETC
key_buffer_size = 32M
max_allowed_packet = 128M
#thread_cache_size=1024
#myisam_sort_buffer_size = 8M
memlock=0
sysdate_is_now=1
thread-cache-size=128
###QUERY CACHE IS DISABLED
###THE QUERY CACHE IN MYSQL CLUSTER CAN HAMPER PERFORMANCE A LOT. HENCE IT IS DISABLED
###BECAUSE INVALIDATION OF IT TAKES TIME (REMEMBER, IT IS A DISTRIBUTED ENVIRONMENT)
###ONLY ENABLE IT AND USE SQL_CACHE TO CACHE ONLY CERTAIN QUERIES ON READONLY TABLES
query_cache_type = 0
query_cache_size = 0


What can I do?