Support Lua scripting and MULTI/EXEC

[stockholmux]

I'd like to be able to do GRAPH.QUERY commands in a Lua script but I get Blocking module command called from Lua script issues. Additionally, I'd like to be able to run MULTI/EXEC blocks but they don't seem to be supported either.

[swilly22]

#352

[mayureshkumbhar]

@swilly22
Tried to execute cypher commands as single transaction using WATCH/MULTI/EXEC, but could its executing as pipeline not transaction. Please find below code for reference.

Third graph CREATE command is failing as one of its param is commented, as expected its failing with redis.clients.jedis.exceptions.JedisDataException: Missing parameters still its not reverting earlier changes done by first two GRAPH CREATE.

try(RedisGraph graph = new RedisGraph();
RedisGraphContext context = graph.getContext()) {
Map<String, Object> params = new HashMap<>();
params.put("age", 30);
//Deliberately commented this line to fail the transaction
//params.put("name", "amit");
// WATCH/MULTI/EXEC
context.watch("contextSocial");
RedisGraphTransaction t = context.multi();
Response r1 = t.query("contextSocial","CREATE (:person{name:'roi',age:32})");
Response rmk = t.query("contextSocial","CREATE (:person{name:'mk',age:30})");
Response r2 = t.query("contextSocial","CREATE (:person{name:$name,age:$age})", params);
Response r3 = t.query("contextSocial", "MATCH (a:person), (b:person) WHERE (a.name = 'roi' AND b.name='mk') CREATE (a)-[:knows]->(b)");
Response r4 = t.query("contextSocial", "MATCH (a:person), (b:person) WHERE (a.name = 'amit' AND b.name='mk') CREATE (a)-[:fof]->(b)");
List execResults = t.exec();
System.out.println(execResults.toString());
//context.deleteGraph("contextSocial");
}
Output

[ResultSetImpl{header=HeaderImpl{schemaTypes=[], schemaNames=[]}, statistics=StatisticsImpl{statistics={Labels added=1, Nodes created=1, Properties set=2, Query internal execution time=0.263100 milliseconds}}, results=[]}, ResultSetImpl{header=HeaderImpl{schemaTypes=[], schemaNames=[]}, statistics=StatisticsImpl{statistics={Nodes created=1, Properties set=2, Query internal execution time=0.107500 milliseconds}}, results=[]}, redis.clients.jedis.exceptions.JedisDataException: Missing parameters, ResultSetImpl{header=HeaderImpl{schemaTypes=[], schemaNames=[]}, statistics=StatisticsImpl{statistics={Relationships created=1, Query internal execution time=0.414600 milliseconds}}, results=[]}, ResultSetImpl{header=HeaderImpl{schemaTypes=[], schemaNames=[]}, statistics=StatisticsImpl{statistics={Query internal execution time=0.277200 milliseconds}}, results=[]}]

[DvirDukhan]

@mayureshkumbhar
As far as I know, the Redis pipeline does not support rollbacks for failing executions within the pipeline, so the success of your first two queries will be shown in your graph. More generally speaking, RedisGraph currently does not support transactions or rollbacks for failing queries.

[mayureshkumbhar]

@DvirDukhan , Is there any way we could implement atomic execution of graph queries or transactional behaviour in Redisgraph

[DvirDukhan]

@mayureshkumbhar
Regarding atomic execution, I think you can use Lua scripts as they are executed on the main thread. But this will not guarantee you the rollback option.
Regarding transactional behavior, I'm sorry, but I think that every solution that I might suggest will probably be wrong since we do not support it. We just started designing transactional behavior on RedisGraph. I cannot commit on the features or ETA since it is in very early stages.

[mayureshkumbhar]

Thank you @DvirDukhan