Checking Repeatable Read Consistency for MariaDB / Galera Cluster

The whole Galera Cluster environment is established on Emulab. I'll update the pure MariaDB version ASAP.

MariaDB version == 10.4.22
Galera Cluster version == 26.4.9

Example Result

The given data in folder output/0/ was generated by Galera engineer from a single MariaDB node, with Galera replication disabled, it violates RR Property.

Parameters:

key_num = 20
client_num = 10
transactions_per_client = 100
operations_per_transaction = 25

Running Steps

1. Run setup_server_node.sh and setup_client_node.sh to set up Galera on server and client nodes respectively.

For three server nodes, change the cluster_name and server_ip in the script. Then run

sh setup_server_node.sh <server_node_no>

For the client nodes, run

sh setup_client_node.sh <server_ip_address>

2. Run init.sh to initialize the Database in Galera Cluster.

Need to change the parameter key if you want to customize the key number.

python3 init.py <server_ip_address>

3. Run galera.py to generate transaction workloads.

Please make sure the server_id are correct, and the key_num is same with settings in init.py. Then run

python3 galera.py -w <wo_rate> -r <ro_rate> -p <w_percent> -t <trans_num> -o <op_num> -c <client_num> -n <thread_no> -f <folder_num>

The collected traces will be stored in folder output/folder_num/ where the trace for each client will be stored in a separate txt file; The default folder_num is 0.

To be noticed, all the read-write transactions generated by this script has been customized, that is, for each transaction, all the read operations will happen before write operations. This part can be modified in function zipf_generator and uniform_generator.

4. Run group_data.py to normalize the collected data into one file result.txt.

python3 group_data.py -o <operation_num> -r <running_times>

The parameter running_times refers to run times j in multi_threads.sh.

5. Run check_rr.py to check if the execution run violates Repeatable Read consistency.

The format of each operation is: read/write(variable, value, client_id, transaction_id), denote as r/w(var, val, cid, tid)

• RR Property:

  For multiple Read operations in the same transaction, r(var, val_1, cid, tid) and r(var, val_2, cid, tid), if there is no Write operation to var between them, then val_1 = val_2.

(Optional) Run multi_threads.sh to automatically generate workloads.

Please change all the parameters regarding ip_address.