data in native distributed NoSQL. But its incom‐ patibility with SQL and imperfection in ecosystem block it from defeating the relational database in the competition, so the relational database still holds database can commit. XA Supported • Support Savepoint; • PostgreSQL/OpenGauss, in the transaction block, the SQL execution is abnormal，then run Com- mit，transactions are automatically rollback; • Support committing and rolling back in other machines after the service is down; • MySQL,in the transaction block, the SQL execution is abnormal, and run Commit, and data re‐ mains consistent. XA Transaction managed

data in native distributed NoSQL. But its incom‐ patibility with SQL and imperfection in ecosystem block it from defeating the relational database in the competition, so the relational database still holds and rolling back in other machines after the service is down. • Savepoint. • In the transaction block, the SQL execution is abnormal, and run Commit, and data remains con‐ sistent. XA Transaction managed time cost of writing packets to client, but it may increase the latency of SQL execution and block other clients if client connections are more than proxy-frontend-executor-size, especially exe‐

data in native distributed NoSQL. But its incom‐ patibility with SQL and imperfection in ecosystem block it from defeating the relational database in the competition, so the relational database still holds commit. XA Transaction Supported • Support Savepoint; • PostgreSQL/OpenGauss, in the transaction block, the SQL execution is abnormal，then run Com- mit，transactions are automatically rollback; • Support committing and rolling back in other machines after the service is down; • MySQL,in the transaction block, the SQL execution is abnormal, and run Commit, and data re‐ mains consistent. BASE Transaction

data in native distributed NoSQL. But its incom‐ patibility with SQL and imperfection in ecosystem block it from defeating the relational database in the competition, so the relational database still holds committing and rolling back in other machines after the service is down. • MySQL, in the transaction block, the SQL execution is abnormal, and run Commit, and data re‐ mains consistent. • After XA transactions compute node in a ShardingSphere cluster exceeds its load, the circuit breaker function is used to block the traffic to the compute node, to ensure that the whole cluster continues to provide stable services

data in native distributed NoSQL. But its incom‐ patibility with SQL and imperfection in ecosystem block it from defeating the relational database in the competition, so the relational database still holds CREATE TABLE IF NOT EX‐ ISTS ˋˋ runoob_tblˋˋ(runoob_id INT UNSIGNED AUTO_ INCRE‐ MENT,runoob_title VARCHAR(100) NOT NULL,runoob_author VARCHAR(40) NOT NULL,runoob_test NATIONAL CH AR(40),submission_date CHARSET=utf8; CREATE TABLE IF NOT EXISTS runoob_tbl ( runoob_id INT UNSIGNED AUTO_INCREMENT, runoob_title VAR‐ CHAR(100) NOT NULL, runoob_author VARCHAR(40) NOT NULL, runoob_test NATIONAL CHAR(40)

data in native distributed NoSQL. But its incom‐ patibility with SQL and imperfection in ecosystem block it from defeating the relational database in the competition, so the relational database still holds commit. XA Transaction Supported • Support Savepoint; • PostgreSQL/OpenGauss, in the transaction block, the SQL execution is abnormal，then run Com- mit，transactions are automatically rollback; • Support committing and rolling back in other machines after the service is down; • MySQL,in the transaction block, the SQL execution is abnormal, and run Commit, and data re‐ mains consistent. BASE Transaction

data in native distributed NoSQL. But its incom‐ patibility with SQL and imperfection in ecosystem block it from defeating the relational database in the competition, so the relational database still holds committing and rolling back in other machines after the service is down. • MySQL, in the transaction block, the SQL execution is abnormal, and run Commit, and data re‐ mains consistent. • After XA transactions compute node in a ShardingSphere cluster exceeds its load, the circuit breaker function is used to block the traffic to the compute node, to ensure that the whole cluster continues to provide stable services

"batchSize":1000,"shardingSize":10000000} | {"workerThread ":20,"batchSize":1000} | {"type":"MEMORY","props":{"block-queue-size":"2000"}} | +--------------------------------------------------------------+------------------- (TYPE(NAME='TPS', PROPERTIES('tps'='2000')))), STREAM_CHANNEL ( TYPE(NAME='MEMORY',PROPERTIES('block-queue-size'='2000'))) ); • 仅修改数据迁移规则中的数据读取配置 9.2. ShardingSphere-Proxy 294 Apache ShardingSphere ); • 仅修改数据迁移规则中的数据通道配置 ALTER MIGRATION RULE ( STREAM_CHANNEL ( TYPE( NAME='MEMORY', PROPERTIES('block-queue-size'='2000'))) ); 保留字 ALTER、MIGRATION、RULE、READ、WRITE、WORKER_THREAD、BATCH_SIZE、SHARDING_SIZE、

"batchSize":1000,"shardingSize":10000000} | {"workerThread ":20,"batchSize":1000} | {"type":"MEMORY","props":{"block-queue-size":"2000"}} | +--------------------------------------------------------------+------------------- (TYPE(NAME='TPS', PROPERTIES('tps'='2000')))), STREAM_CHANNEL ( TYPE(NAME='MEMORY',PROPERTIES('block-queue-size'='2000'))) ); • 仅修改数据迁移规则中的数据读取配置 9.2. ShardingSphere-Proxy 288 Apache ShardingSphere ); • 仅修改数据迁移规则中的数据通道配置 ALTER MIGRATION RULE ( STREAM_CHANNEL ( TYPE( NAME='MEMORY', PROPERTIES('block-queue-size'='2000'))) ); 保留字 ALTER、MIGRATION、RULE、READ、WRITE、WORKER_THREAD、BATCH_SIZE、SHARDING_SIZE、

"batchSize":1000,"shardingSize":10000000} | {"workerThread ":20,"batchSize":1000} | {"type":"MEMORY","props":{"block-queue-size":"2000"}} | +--------------------------------------------------------------+------------------- (TYPE(NAME='TPS', PROPERTIES('tps'='2000')))), STREAM_CHANNEL ( TYPE(NAME='MEMORY',PROPERTIES('block-queue-size'='2000'))) ); 保留字 ALTER、MIGRATION、RULE、READ、WRITE、WORKER_THREAD、BATCH_SIZE、SHARDING_SIZE、 "batchSize":1000,"shardingSize":10000000} | {"workerThread ":20,"batchSize":1000} | {"type":"MEMORY","props":{"block-queue-size":"2000"}} | 9.2. ShardingSphere-Proxy 373 Apache ShardingSphere document +---------