Hi, We are trying to connect more than two JBoss-instances with one instance of maxdb(on Linux). We first ran into problems when trying to connect the second JBoss, but were able to solve them by increasing the value of MAX_USER_TASKS to 380. When we tried to connect the 3rd JBoss the database says "could not create communication semaphore" and rejects all further connection attemps by JBoss's JDBC driver. We then increased the MAX_USER_TASKS value by tweaking the maximum shared memory value with "sysctl -w kernel.shmmax=134217738" to 1400, but that didn't help. MaxDB still crashes at about 150 sessions opened by the JBoss-servers.
So any suggestions how to solve this (see at the end for details about our current parameters/setup)? Thanks in advance, Artur We are currently using the follwoing setup: -one instance of maxdb running with 2 GB memory and 2x3.2 GHz Xeon CPus with Hyperthreading on Linux 2.6.15.1 -all JBoss-Servers on XEN 2 Virtual Machines with 830 MB of memory in the same subnet -http-session loadbalancing with apache-ssl/mod-jk KERNELVERSION KERNEL 7.5.0 BUILD 031-000-DEB-001 INSTANCE_TYPE OLTP MCOD YES MAXLOGVOLUMES 2 MAXDATAVOLUMES 11 MAXBACKUPDEVS 2 LOG_MIRRORED NO MAXCPU 4 MAXUSERTASKS 1400 MAXLOCKS 57280 CACHE_SIZE 80000 RUNDIRECTORY /var/lib/maxdb/data/wrk/PDB OPMSG1 /dev/console OPMSG2 /dev/null LOG_SEGMENT_SIZE 200000 KERNELVERSION KERNEL 7.5.0 BUILD 031-000-DEB-001 INSTANCE_TYPE OLTP MCOD YES MAXLOGVOLUMES 2 MAXDATAVOLUMES 11 MAXBACKUPDEVS 2 LOG_MIRRORED NO MAXCPU 4 MAXUSERTASKS 1400 MAXLOCKS 57280 CACHE_SIZE 80000 RUNDIRECTORY /var/lib/maxdb/data/wrk/PDB OPMSG1 /dev/console OPMSG2 /dev/null LOG_SEGMENT_SIZE 200000 _UNICODE NO DEFAULT_CODE ASCII DATE_TIME_FORMAT INTERNAL LOG_BACKUP_TO_PIPE NO BACKUP_BLOCK_CNT 8 LOG_IO_QUEUE 50 _TRANS_RGNS 8 _TAB_RGNS 8 _ROW_RGNS 8 MAXSERVERTASKS 30 DEADLOCK_DETECTION 4 SESSION_TIMEOUT 900 REQUEST_TIMEOUT 5000 LRU_FOR_SCAN NO CAT_CACHE_SUPPLY 44832 MP_RGN_LOOP 100 MAXRGN_REQUEST 3000 XP_DATA_CACHE_RGNS 0 _DATA_CACHE_RGNS 32 XP_CONVERTER_REGIONS 0 CONVERTER_REGIONS 8 XP_MAXPAGER 0 SEQUENCE_CACHE 1 VOLUMENO_BIT_COUNT 8 OPTIM_MAX_MERGE 500 OPTIM_INV_ONLY YES JOIN_SEARCH_LEVEL 0 JOIN_MAXTAB_LEVEL4 16 JOIN_MAXTAB_LEVEL9 5 KERNELDIAGSIZE 800 _MAXEVENTS 200 TRACE_PAGES_TI 2 TRACE_PAGES_GC 0 TRACE_PAGES_LW 5 TRACE_PAGES_PG 3 TRACE_PAGES_US 10 TRACE_PAGES_UT 5 TRACE_PAGES_SV 5 TRACE_PAGES_EV 2 TRACE_PAGES_BUP 0 UTILITY_PROTSIZE 100 _MAX_MESSAGE_FILES 0 _EVENT_ALIVE_CYCLE 0 DIAG_HISTORY_NUM 2 DIAG_HISTORY_PATH /var/lib/maxdb/data/wrk/XPDB/DIAGHISTORY _COMMENT FORMATTING_MODE PARALLEL FORMAT_DATAVOLUME YES OFFICIAL_NODE LOAD_BALANCING_CHK 0 HS_STORAGE_DLL libhsscopy HS_NODE_? HS_DELAY_TIME_? HS_SYNC_INTERVAL 50 JOIN_OPERATOR_IMPLEMENTATION YES JOIN_TABLEBUFFER 128 SHAREDSQL NO SHAREDSQL_EXPECTEDSTATEMENTCOUNT 1500 SHAREDSQL_COMMANDCACHESIZE 32768 MEMORY_ALLOCATION_LIMIT 0 MIN_RETENTION_TIME 60 MAX_RETENTION_TIME 480 MAX_SINGLE_HASHTABLE_SIZE 512 MAX_HASHTABLE_MEMORY 5120 HASHED_RESULTSET YES HASHED_RESULTSET_CACHESIZE 262144 AUTO_RECREATE_BAD_INDEXES NO LOCAL_REDO_LOG_BUFFER_SIZE 0 -- MaxDB Discussion Mailing List For list archives: http://lists.mysql.com/maxdb To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
