On Fri, Jan 15, 2010 at 8:58 AM, Raffaele Camarda <raffaele.camarda@gmail.com> wrote:
I was hitting the same problem last days so i went through some test, the configuration you suggest is quite nice and according to my result yun anticipated me on the problem doing my next step ;).

basicly i was wondering using MySQL Cluster and a Cluster MySQL for some different services. Setting the point that mysql cluster was taken in account for availability specs more than for its performance.

That said here some spec data:

hp/ibm dual quadcore with SAS RAID and 8GB of RAM. (for dom0)
OS: Centos 5.3
Virtualization: xen

for real server no SAS but SATA RAID and 4GB of RAM

I got 4 of the former and 2 of the latter.
All domus where on .img files.

Used sysbench for testing

i tested: mysql cluster on domUs, mysql on domu and mysql on real server 

I got real pour performance with mysql cluster on domus no data for that, but no optimiziation was done.

Moreover consider that no optimizatino was done for none of the configurations.

No conclusion at all, more serious efforts can be done for getting the best from each donfiguration, so just get this datas as a non production test, which is what it is.

Here some numbers hope they are usefull:

***************************Mysql cluster on real server (SATA + 4GB) ********************
sysbench --num-threads=4 --max-requests=20000 --test=oltp --mysql-db=sbtest --mysql-user=test --mysql-password=*********** --mysql-host=************** --mysql-port=********* --mysql-table-engine=ndbcluster --oltp-test-mode=complex run

OLTP test statistics:
    queries performed:
        read:                            280000
        write:                           100000
        other:                           40000
        total:                           420000
    transactions:                        20000  (440.95 per sec.)
    deadlocks:                           0      (0.00 per sec.)
    read/write requests:                 380000 (8378.12 per sec.)
    other operations:                    40000  (881.91 per sec.)

Test execution summary:
    total time:                          45.3563s
    total number of events:              20000
    total time taken by event execution: 181.2726
    per-request statistics:
         min:                                  5.72ms
         avg:                                  9.06ms
         max:                                154.81ms
         approx.  95 percentile:              10.30ms

Threads fairness:
    events (avg/stddev):           5000.0000/2.74
    execution time (avg/stddev):   45.3182/0.00


******************** Plain Mysql on xen domu *************************
OLTP test statistics:
    queries performed:
        read:                            280000
        write:                           100000
        other:                           40000
        total:                           420000
    transactions:                        20000  (368.68 per sec.)
    deadlocks:                           0      (0.00 per sec.)
    read/write requests:                 380000 (7004.93 per sec.)
    other operations:                    40000  (737.36 per sec.)

Test execution summary:
    total time:                          54.2475s
    total number of events:              20000
    total time taken by event execution: 216.8328
    per-request statistics:
         min:                                  6.35ms
         avg:                                 10.84ms
         max:                                263.48ms
         approx.  95 percentile:              11.14ms

Threads fairness:
    events (avg/stddev):           5000.0000/2.45
    execution time (avg/stddev):   54.2082/0.00


******************* Finally mysql on real server (SATA + 4GB) ***************
OLTP test statistics:
    queries performed:
        read:                            280000
        write:                           100000
        other:                           40000
        total:                           420000
    transactions:                        20000  (467.17 per sec.)
    deadlocks:                           0      (0.00 per sec.)
    read/write requests:                 380000 (8876.18 per sec.)
    other operations:                    40000  (934.33 per sec.)

Test execution summary:
    total time:                          42.8112s
    total number of events:              20000
    total time taken by event execution: 171.0977
    per-request statistics:
         min:                                  5.67ms
         avg:                                  8.55ms
         max:                                133.64ms
         approx.  95 percentile:               9.84ms

Threads fairness:
    events (avg/stddev):           5000.0000/2.55
    execution time (avg/stddev):   42.7744/0.00


2010/1/15 compdoc <compdoc@hotrodpc.com>



Don't use .img files for Databases! I've done the mysqlbench test on the same machine with the same database with using LVM and img files and with .img files I got within 5% of the Dom0 speed. When I moved the DomU to using LVM I got within 1% of Dom0 speed. This is the one instance where there's a definite advantage to LVM over img files.

Grant McWilliams