Closed shiqstone closed 4 years ago
rencalo770
commented
4 years ago Thanks for your issue! Can I have a look of your rule?
Generally speaking, you should make sure the API you called in conc{} should be thread safety or no same API invoked in the same conc{} at the same time! Because the framework does not know what API will be invoked in this concurrent block.
shiqstone
commented
4 years ago here is the code
func invoker(userNo string, id int) (bool, error) {
//try get ruleStr by id
//example
// `BEGIN
// conc {
// ur_relrk1 = IsHitEvent(User.UserNo, "event_fact_1", param_relrk1)
// ur_relrk3 = IsHitEvent(User.UserNo, "event_fact_2", param_relrk3)
// // dynamic generation
// }
// User.Result = IsHit("and", ur_relrk1, ur_relrk3)
// END`
ruleStr := GetRuleById(id)
user := &EvCbUser{
UserNo: userNo,
Result: false,
}
dataContext := context.NewDataContext()
//inject function
dataContext.Add("IsHitEvent", IsHitEvent)
dataContext.Add("IsHit", IsHit)
//inject struct
dataContext.Add("User", user)
//must default false
stag := &engine.Stag{StopTag: false}
dataContext.Add("stag", stag)
//init rule engine
knowledgeContext := grbase.NewKnowledgeContext()
ruleBuilder := builder.NewRuleBuilder(knowledgeContext, dataContext)
//resolve rules from string
start1 := time.Now().UnixNano()
err := ruleBuilder.BuildRuleFromString(ruleStr)
end1 := time.Now().UnixNano()
logs.Info("rules num:%d, load rules cost time:%d ns", len(knowledgeContext.RuleEntities), end1-start1)
if err != nil {
logs.Error("err: ", err)
} else {
eng := engine.NewGengine()
start := time.Now().UnixNano()
// true: means when there are many rules， if one rule execute error，continue to execute rules after the occur error rule
err := eng.ExecuteWithStopTagDirect(ruleBuilder, true, stag)
end := time.Now().UnixNano()
if err != nil {
logs.Error("execute rule error: %v", err)
}
logs.Info("execute rule cost %d ns", end-start)
}
return user.Result, nil
}
func IsHitEvent(userNo string, conf string, param string) bool {
//biz process, no concurrent block
//TEST this will cause crash
panic("unexpected error")
}
func IsHit(op string, pol ...bool) (res bool) {
//biz process
}I try to add follow code into conc_statement.go, main thread would continue run, i'm not sure is this ok
conc_statement.go
95. go func() {
96. defer func() {
97. if err := recover(); err != nil {
98. logrus.Errorf("concStatement execute error and recover: %v", err)
99. }
100. wg.Done()
101. }()
102. _, e := assignment.Evaluate(Vars)
`Thanks for your code and your more idea !
func() {
defer func() {
if err := recover(); err != nil {
logrus.Errorf("concStatement execute error and recover: %v", err)
}
wg.Done()
}()
_, e := assignment.Evaluate(Vars)This code is a method that golang helps application still run when there is panic. why we don't add this code to gengine, because we have to consider two conditions:
One is that the panic is caused by user's API, in framework gengine, it has no enough msg to decide whether the panic is needed to be recoverd! In fact, if the panic the user's API caused and should be recoverd, user should know it, and user should handle this panic recovery in their own API , not gengine do it, and gengine is unaware of user's panic recovery, this also could avoid causing unknown problems for user. this is not only fit for "conc{}", but also fit for every execute in gengine.
The other one is that the panic is cause by gengine. if user using gengine has followed the specification, it means the panic is not panic, the panic is a bug to gengine, and we must fix it for our user.
But wise approach to recovery panic is in application service framework, not one recovery for one panic in user‘s API. Such as in our company, we make gengine as a API to execute in grpc service. grpc framework will recover the panic to keep the service continue running to serve for the next requests!
rencalo770
commented
4 years ago here is the code
func invoker(userNo string, id int) (bool, error) { //try get ruleStr by id //example // `BEGIN // conc { // ur_relrk1 = IsHitEvent(User.UserNo, "event_fact_1", param_relrk1) // ur_relrk3 = IsHitEvent(User.UserNo, "event_fact_2", param_relrk3) // // dynamic generation // } // User.Result = IsHit("and", ur_relrk1, ur_relrk3) // END` ruleStr := GetRuleById(id) user := &EvCbUser{ UserNo: userNo, Result: false, } dataContext := context.NewDataContext() //inject function dataContext.Add("IsHitEvent", IsHitEvent) dataContext.Add("IsHit", IsHit) //inject struct dataContext.Add("User", user) //must default false stag := &engine.Stag{StopTag: false} dataContext.Add("stag", stag) //init rule engine knowledgeContext := grbase.NewKnowledgeContext() ruleBuilder := builder.NewRuleBuilder(knowledgeContext, dataContext) //resolve rules from string start1 := time.Now().UnixNano() err := ruleBuilder.BuildRuleFromString(ruleStr) end1 := time.Now().UnixNano() logs.Info("rules num:%d, load rules cost time:%d ns", len(knowledgeContext.RuleEntities), end1-start1) if err != nil { logs.Error("err: ", err) } else { eng := engine.NewGengine() start := time.Now().UnixNano() // true: means when there are many rules， if one rule execute error，continue to execute rules after the occur error rule err := eng.ExecuteWithStopTagDirect(ruleBuilder, true, stag) end := time.Now().UnixNano() if err != nil { logs.Error("execute rule error: %v", err) } logs.Info("execute rule cost %d ns", end-start) } return user.Result, nil } func IsHitEvent(userNo string, conf string, param string) bool { //biz process, no concurrent block //TEST this will cause crash panic("unexpected error") } func IsHit(op string, pol ...bool) (res bool) { //biz process }
please, pay attention to your this code: In any computer language, compile code is a cost-time and CPU intensive thing, it is also in gengine, so you should separate the rule build process and the engine execute process, and if you want to update your rules when gengine running,you should do as below:
https://rencalo770.github.io/gengine_en/#/example
type MyService struct{
Kc *base.KnowledgeContext
Dc *context.DataContext
Rb *builder.RuleBuilder
Gengine *engine.Gengine
//field...
}
//init
func NewMyService(ruleStr string, /* other params */ ) *MyService {
dataContext := context.NewDataContext()
// there add what you want to use in every request
dataContext.Add("println", fmt.Println)
knowledgeContext := base.NewKnowledgeContext()
ruleBuilder := builder.NewRuleBuilder(knowledgeContext, dataContext)
e := ruleBuilder.BuildRuleFromString(ruleStr)
if e != nil {
panic(e)
}
gengine := engine.NewGengine()
return &MyService{
Kc : knowledgeContext,
Dc : dataContext,
Rb : ruleBuilder,
Gengine : gengine,
}
}
// when user want to update rules in running time, use it
func (ms *MyService)UpdateRule(newRuleStr string) error {
rb := builder.NewRuleBuilder(ms.Kc, ms.Dc)
e := rb.BuildRuleFromString(newRuleStr)
if e != nil {
return e
}
//replace old ptr
ms.Rb = rb
return nil
}
//service
func (ms *MyService) Service(name string, req interface{}) error {
ms.Dc.Add(name, req)
e := ms.Gengine.Execute(ms.Rb, true)
return e
}
recover the panic
Kind of understand, so is that ok if i recover the panic in my function "IsHitEvent" ?
shiqstone
commented
4 years ago here is the code
func invoker(userNo string, id int) (bool, error) { //try get ruleStr by id //example // `BEGIN // conc { // ur_relrk1 = IsHitEvent(User.UserNo, "event_fact_1", param_relrk1) // ur_relrk3 = IsHitEvent(User.UserNo, "event_fact_2", param_relrk3) // // dynamic generation // } // User.Result = IsHit("and", ur_relrk1, ur_relrk3) // END` ruleStr := GetRuleById(id) user := &EvCbUser{ UserNo: userNo, Result: false, } dataContext := context.NewDataContext() //inject function dataContext.Add("IsHitEvent", IsHitEvent) dataContext.Add("IsHit", IsHit) //inject struct dataContext.Add("User", user) //must default false stag := &engine.Stag{StopTag: false} dataContext.Add("stag", stag) //init rule engine knowledgeContext := grbase.NewKnowledgeContext() ruleBuilder := builder.NewRuleBuilder(knowledgeContext, dataContext) //resolve rules from string start1 := time.Now().UnixNano() err := ruleBuilder.BuildRuleFromString(ruleStr) end1 := time.Now().UnixNano() logs.Info("rules num:%d, load rules cost time:%d ns", len(knowledgeContext.RuleEntities), end1-start1) if err != nil { logs.Error("err: ", err) } else { eng := engine.NewGengine() start := time.Now().UnixNano() // true: means when there are many rules， if one rule execute error，continue to execute rules after the occur error rule err := eng.ExecuteWithStopTagDirect(ruleBuilder, true, stag) end := time.Now().UnixNano() if err != nil { logs.Error("execute rule error: %v", err) } logs.Info("execute rule cost %d ns", end-start) } return user.Result, nil } func IsHitEvent(userNo string, conf string, param string) bool { //biz process, no concurrent block //TEST this will cause crash panic("unexpected error") } func IsHit(op string, pol ...bool) (res bool) { //biz process }please, pay attention to your this code: In any computer language, compile code is a cost-time and CPU intensive thing, it is also in gengine, so you should separate the rule build process and the engine execute process, and if you want to update your rules when gengine running,you should do as below:
https://rencalo770.github.io/gengine_en/#/example
type MyService struct{ Kc *base.KnowledgeContext Dc *context.DataContext Rb *builder.RuleBuilder Gengine *engine.Gengine //field... } //init func NewMyService(ruleStr string, /* other params */ ) *MyService { dataContext := context.NewDataContext() // there add what you want to use in every request dataContext.Add("println", fmt.Println) knowledgeContext := base.NewKnowledgeContext() ruleBuilder := builder.NewRuleBuilder(knowledgeContext, dataContext) e := ruleBuilder.BuildRuleFromString(ruleStr) if e != nil { panic(e) } gengine := engine.NewGengine() return &MyService{ Kc : knowledgeContext, Dc : dataContext, Rb : ruleBuilder, Gengine : gengine, } } // when user want to update rules in running time, use it func (ms *MyService)UpdateRule(newRuleStr string) error { rb := builder.NewRuleBuilder(ms.Kc, ms.Dc) e := rb.BuildRuleFromString(newRuleStr) if e != nil { return e } //replace old ptr ms.Rb = rb return nil } //service func (ms *MyService) Service(name string, req interface{}) error { ms.Dc.Add(name, req) e := ms.Gengine.Execute(ms.Rb, true) return e }
thanks for your advice, i'll try to refactor my code.
rencalo770
commented
4 years ago Yeah, also thanks your attention! And we updated the version to v1.2.0, and the framework become more clear and easy to understand. all doc are also updated, just need make a little change to move from old version to new version.
rencalo770
commented
4 years ago recover the panic
Kind of understand, so is that ok if i recover the panic in my function "IsHitEvent" ?
it should be in IsHitEvent if IsHitEvent is independent service, if not, the recovery should in the top service which contains IsHitEvent , gengine and the other servives.
I meet a problem to use "conc{}" to run rules, when there is panic happens for some reason, web service main thread will crash and service stop. seem like it wouldn't happen in non-concurrent. how can i recover the service?