Is it a bad practice to switch threads within a transaction?
I wonder if switching threads within a transaction is simply asking for troubles?
Since following code is blocking one thread and doing things in other threads, it seems a waste, there must be better way than this, any advice or idea are welcome. Thanks in advance.
I am trying to load Something from database and save it after made some changes:
public Mono<SomeThing> updateSomething(int i) {
TransactionStatus tx = openTx();
return Mono.just(i)
.publishOn(workerThread)
.flatMap(this::loadSomethingFromDbById)
.map(Something::doSomeChange)
.flatMap(this::saveSomethingToDb)
.publishOn(Schedulers.immediate())
.doFinally(s -> closeTx(s));
}
public void blockingUpdateSomething() {
updateSomething(1).block();
}
- openTx/closeTx() are simple wrappers of PlatformTransactionManager, and .block() is used to keep this thread from other Transactions, can they work correctly?
- Mono<> is used to switch threads, which limits concurrent calls to the spring-data's JpaRepository, any better ways doing the limit?
Update:
Although the code could be more conventional if run in one thread synchronously, there might be a problem when there are lots of such threads.
Let's say 1000 threads do all jobs in their own thread, they might cause high cpu contentions.
Instead, if we offload jobs to limited threads, leaving those 1000 threads waiting for some result, the cpu contention should be less.
So, I might prefer the original thread dancing code, if transaction works well in that.
java spring-transactions project-reactor
asked Nov 16 '18 at 1:20
SlackerSlacker
558
add a comment |
I wonder if switching threads within a transaction is simply asking for troubles?
Since following code is blocking one thread and doing things in other threads, it seems a waste, there must be better way than this, any advice or idea are welcome. Thanks in advance.
I am trying to load Something from database and save it after made some changes:
public Mono<SomeThing> updateSomething(int i) {
TransactionStatus tx = openTx();
return Mono.just(i)
.publishOn(workerThread)
.flatMap(this::loadSomethingFromDbById)
.map(Something::doSomeChange)
.flatMap(this::saveSomethingToDb)
.publishOn(Schedulers.immediate())
.doFinally(s -> closeTx(s));
}
public void blockingUpdateSomething() {
updateSomething(1).block();
}
- openTx/closeTx() are simple wrappers of PlatformTransactionManager, and .block() is used to keep this thread from other Transactions, can they work correctly?
- Mono<> is used to switch threads, which limits concurrent calls to the spring-data's JpaRepository, any better ways doing the limit?
Update:
Although the code could be more conventional if run in one thread synchronously, there might be a problem when there are lots of such threads.
Let's say 1000 threads do all jobs in their own thread, they might cause high cpu contentions.
Instead, if we offload jobs to limited threads, leaving those 1000 threads waiting for some result, the cpu contention should be less.
So, I might prefer the original thread dancing code, if transaction works well in that.
java spring-transactions project-reactor
asked Nov 16 '18 at 1:20
SlackerSlacker
558
Feels like a very, very bad idea. I'd wonder why you're even asking.
– duffymo
Nov 16 '18 at 1:48
So, I guess I should never switch thread within transactions then? I'm asking because I wonder how to do transaction right, sorry if my code is too far away from that.
– Slacker
Nov 16 '18 at 2:19
Do it right? Don't switch threads.
– duffymo
Nov 16 '18 at 10:26
add a comment |
I wonder if switching threads within a transaction is simply asking for troubles?
Since following code is blocking one thread and doing things in other threads, it seems a waste, there must be better way than this, any advice or idea are welcome. Thanks in advance.
I am trying to load Something from database and save it after made some changes:
public Mono<SomeThing> updateSomething(int i) {
TransactionStatus tx = openTx();
return Mono.just(i)
.publishOn(workerThread)
.flatMap(this::loadSomethingFromDbById)
.map(Something::doSomeChange)
.flatMap(this::saveSomethingToDb)
.publishOn(Schedulers.immediate())
.doFinally(s -> closeTx(s));
}
public void blockingUpdateSomething() {
updateSomething(1).block();
}
- openTx/closeTx() are simple wrappers of PlatformTransactionManager, and .block() is used to keep this thread from other Transactions, can they work correctly?
- Mono<> is used to switch threads, which limits concurrent calls to the spring-data's JpaRepository, any better ways doing the limit?
Update:
Although the code could be more conventional if run in one thread synchronously, there might be a problem when there are lots of such threads.
Let's say 1000 threads do all jobs in their own thread, they might cause high cpu contentions.
Instead, if we offload jobs to limited threads, leaving those 1000 threads waiting for some result, the cpu contention should be less.
So, I might prefer the original thread dancing code, if transaction works well in that.
java spring-transactions project-reactor
asked Nov 16 '18 at 1:20
SlackerSlacker
558
I wonder if switching threads within a transaction is simply asking for troubles?
Since following code is blocking one thread and doing things in other threads, it seems a waste, there must be better way than this, any advice or idea are welcome. Thanks in advance.
I am trying to load Something from database and save it after made some changes:
public Mono<SomeThing> updateSomething(int i) {
TransactionStatus tx = openTx();
return Mono.just(i)
.publishOn(workerThread)
.flatMap(this::loadSomethingFromDbById)
.map(Something::doSomeChange)
.flatMap(this::saveSomethingToDb)
.publishOn(Schedulers.immediate())
.doFinally(s -> closeTx(s));
}
public void blockingUpdateSomething() {
updateSomething(1).block();
}
- openTx/closeTx() are simple wrappers of PlatformTransactionManager, and .block() is used to keep this thread from other Transactions, can they work correctly?
- Mono<> is used to switch threads, which limits concurrent calls to the spring-data's JpaRepository, any better ways doing the limit?
Update:
Although the code could be more conventional if run in one thread synchronously, there might be a problem when there are lots of such threads.
Let's say 1000 threads do all jobs in their own thread, they might cause high cpu contentions.
Instead, if we offload jobs to limited threads, leaving those 1000 threads waiting for some result, the cpu contention should be less.
So, I might prefer the original thread dancing code, if transaction works well in that.
java spring-transactions project-reactor
java spring-transactions project-reactor
asked Nov 16 '18 at 1:20
SlackerSlacker
558
asked Nov 16 '18 at 1:20
SlackerSlacker
558
edited Nov 16 '18 at 7:31
Slacker
asked Nov 16 '18 at 1:20
SlackerSlacker
558
asked Nov 16 '18 at 1:20
SlackerSlacker
558
asked Nov 16 '18 at 1:20
SlackerSlacker
558
558
Feels like a very, very bad idea. I'd wonder why you're even asking.
– duffymo
Nov 16 '18 at 1:48
So, I guess I should never switch thread within transactions then? I'm asking because I wonder how to do transaction right, sorry if my code is too far away from that.
– Slacker
Nov 16 '18 at 2:19
Do it right? Don't switch threads.
– duffymo
Nov 16 '18 at 10:26
add a comment |
Feels like a very, very bad idea. I'd wonder why you're even asking.
– duffymo
Nov 16 '18 at 1:48
So, I guess I should never switch thread within transactions then? I'm asking because I wonder how to do transaction right, sorry if my code is too far away from that.
– Slacker
Nov 16 '18 at 2:19
Do it right? Don't switch threads.
– duffymo
Nov 16 '18 at 10:26
Feels like a very, very bad idea. I'd wonder why you're even asking.
– duffymo
Nov 16 '18 at 1:48
Feels like a very, very bad idea. I'd wonder why you're even asking.
– duffymo
Nov 16 '18 at 1:48
So, I guess I should never switch thread within transactions then? I'm asking because I wonder how to do transaction right, sorry if my code is too far away from that.
– Slacker
Nov 16 '18 at 2:19
So, I guess I should never switch thread within transactions then? I'm asking because I wonder how to do transaction right, sorry if my code is too far away from that.
– Slacker
Nov 16 '18 at 2:19
Do it right? Don't switch threads.
– duffymo
Nov 16 '18 at 10:26
Do it right? Don't switch threads.
– duffymo
Nov 16 '18 at 10:26
add a comment |
1 Answer
1
active
oldest
votes
Answering your question, yes it is a bad practice to switch threads within a transaction. However your code doesn't seem to be doing that, it's just using a non-conventional way to lock a shared resource.
answered Nov 16 '18 at 2:53
Perdi EstaquelPerdi Estaquel
6691520
I think if I recode it like: @Transactional public SomeThing updateSomething(int i) { Something st = loadSomethingFromDbById(i); st.doSomeChange(); return saveSomethingToDb(st); } It's more conventional, but could not do things parallel, e.g. make two http request same time. Is that correct? Sorry for the formatting, can't get it right.
– Slacker
Nov 16 '18 at 6:24
add a comment |
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1 Answer
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1 Answer
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votes
Answering your question, yes it is a bad practice to switch threads within a transaction. However your code doesn't seem to be doing that, it's just using a non-conventional way to lock a shared resource.
answered Nov 16 '18 at 2:53
Perdi EstaquelPerdi Estaquel
6691520
I think if I recode it like: @Transactional public SomeThing updateSomething(int i) { Something st = loadSomethingFromDbById(i); st.doSomeChange(); return saveSomethingToDb(st); } It's more conventional, but could not do things parallel, e.g. make two http request same time. Is that correct? Sorry for the formatting, can't get it right.
– Slacker
Nov 16 '18 at 6:24
add a comment |
Answering your question, yes it is a bad practice to switch threads within a transaction. However your code doesn't seem to be doing that, it's just using a non-conventional way to lock a shared resource.
answered Nov 16 '18 at 2:53
Perdi EstaquelPerdi Estaquel
6691520
I think if I recode it like: @Transactional public SomeThing updateSomething(int i) { Something st = loadSomethingFromDbById(i); st.doSomeChange(); return saveSomethingToDb(st); } It's more conventional, but could not do things parallel, e.g. make two http request same time. Is that correct? Sorry for the formatting, can't get it right.
– Slacker
Nov 16 '18 at 6:24
add a comment |
Answering your question, yes it is a bad practice to switch threads within a transaction. However your code doesn't seem to be doing that, it's just using a non-conventional way to lock a shared resource.
answered Nov 16 '18 at 2:53
Perdi EstaquelPerdi Estaquel
6691520
Answering your question, yes it is a bad practice to switch threads within a transaction. However your code doesn't seem to be doing that, it's just using a non-conventional way to lock a shared resource.
answered Nov 16 '18 at 2:53
Perdi EstaquelPerdi Estaquel
6691520
answered Nov 16 '18 at 2:53
Perdi EstaquelPerdi Estaquel
6691520
answered Nov 16 '18 at 2:53
Perdi EstaquelPerdi Estaquel
6691520
answered Nov 16 '18 at 2:53
Perdi EstaquelPerdi Estaquel
6691520
6691520
I think if I recode it like: @Transactional public SomeThing updateSomething(int i) { Something st = loadSomethingFromDbById(i); st.doSomeChange(); return saveSomethingToDb(st); } It's more conventional, but could not do things parallel, e.g. make two http request same time. Is that correct? Sorry for the formatting, can't get it right.
– Slacker
Nov 16 '18 at 6:24
add a comment |
I think if I recode it like: @Transactional public SomeThing updateSomething(int i) { Something st = loadSomethingFromDbById(i); st.doSomeChange(); return saveSomethingToDb(st); } It's more conventional, but could not do things parallel, e.g. make two http request same time. Is that correct? Sorry for the formatting, can't get it right.
– Slacker
Nov 16 '18 at 6:24
I think if I recode it like: @Transactional public SomeThing updateSomething(int i) { Something st = loadSomethingFromDbById(i); st.doSomeChange(); return saveSomethingToDb(st); } It's more conventional, but could not do things parallel, e.g. make two http request same time. Is that correct? Sorry for the formatting, can't get it right.
– Slacker
Nov 16 '18 at 6:24
I think if I recode it like: @Transactional public SomeThing updateSomething(int i) { Something st = loadSomethingFromDbById(i); st.doSomeChange(); return saveSomethingToDb(st); } It's more conventional, but could not do things parallel, e.g. make two http request same time. Is that correct? Sorry for the formatting, can't get it right.
– Slacker
Nov 16 '18 at 6:24
add a comment |
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Feels like a very, very bad idea. I'd wonder why you're even asking.
– duffymo
Nov 16 '18 at 1:48
So, I guess I should never switch thread within transactions then? I'm asking because I wonder how to do transaction right, sorry if my code is too far away from that.
– Slacker
Nov 16 '18 at 2:19
Do it right? Don't switch threads.
– duffymo
Nov 16 '18 at 10:26