Re: Join DStream With Other Datasets
I don't think this has anything to do with transferring anything from the driver, or per task. I'm talking about a singleton object in the JVM that loads whatever you want from wherever you want and holds it in memory once per JVM. That is, I do not think you have to use broadcast, or even any Spark mechanism. On Mon, Jan 19, 2015 at 2:35 AM, Ji ZHANG wrote: > Hi Sean, > > Thanks for your advice, a normal 'val' will suffice. But will it be > serialized and transferred every batch and every partition? That's why > broadcast exists, right? > > For now I'm going to use 'val', but I'm still looking for a broadcast-way > solution. > > > On Sun, Jan 18, 2015 at 5:36 PM, Sean Owen wrote: >> >> I think that this problem is not Spark-specific since you are simply side >> loading some data into memory. Therefore you do not need an answer that uses >> Spark. >> >> Simply load the data and then poll for an update each time it is accessed? >> Or some reasonable interval? This is just something you write in Java/Scala. >> >> On Jan 17, 2015 2:06 PM, "Ji ZHANG" wrote: >>> >>> Hi, >>> >>> I want to join a DStream with some other dataset, e.g. join a click >>> stream with a spam ip list. I can think of two possible solutions, one >>> is use broadcast variable, and the other is use transform operation as >>> is described in the manual. >>> >>> But the problem is the spam ip list will be updated outside of the >>> spark streaming program, so how can it be noticed to reload the list? >>> >>> For broadcast variables, they are immutable. >>> >>> For transform operation, is it costly to reload the RDD on every >>> batch? If it is, and I use RDD.persist(), does it mean I need to >>> launch a thread to regularly unpersist it so that it can get the >>> updates? >>> >>> Any ideas will be appreciated. Thanks. >>> >>> -- >>> Jerry >>> >>> - >>> To unsubscribe, e-mail: user-unsubscr...@spark.apache.org >>> For additional commands, e-mail: user-h...@spark.apache.org >>> > > > > -- > Jerry - To unsubscribe, e-mail: user-unsubscr...@spark.apache.org For additional commands, e-mail: user-h...@spark.apache.org
Re: Join DStream With Other Datasets
Hi Sean, Thanks for your advice, a normal 'val' will suffice. But will it be serialized and transferred every batch and every partition? That's why broadcast exists, right? For now I'm going to use 'val', but I'm still looking for a broadcast-way solution. On Sun, Jan 18, 2015 at 5:36 PM, Sean Owen wrote: > I think that this problem is not Spark-specific since you are simply side > loading some data into memory. Therefore you do not need an answer that > uses Spark. > > Simply load the data and then poll for an update each time it is accessed? > Or some reasonable interval? This is just something you write in Java/Scala. > On Jan 17, 2015 2:06 PM, "Ji ZHANG" wrote: > >> Hi, >> >> I want to join a DStream with some other dataset, e.g. join a click >> stream with a spam ip list. I can think of two possible solutions, one >> is use broadcast variable, and the other is use transform operation as >> is described in the manual. >> >> But the problem is the spam ip list will be updated outside of the >> spark streaming program, so how can it be noticed to reload the list? >> >> For broadcast variables, they are immutable. >> >> For transform operation, is it costly to reload the RDD on every >> batch? If it is, and I use RDD.persist(), does it mean I need to >> launch a thread to regularly unpersist it so that it can get the >> updates? >> >> Any ideas will be appreciated. Thanks. >> >> -- >> Jerry >> >> - >> To unsubscribe, e-mail: user-unsubscr...@spark.apache.org >> For additional commands, e-mail: user-h...@spark.apache.org >> >> -- Jerry
Re: Join DStream With Other Datasets
I think that this problem is not Spark-specific since you are simply side loading some data into memory. Therefore you do not need an answer that uses Spark. Simply load the data and then poll for an update each time it is accessed? Or some reasonable interval? This is just something you write in Java/Scala. On Jan 17, 2015 2:06 PM, "Ji ZHANG" wrote: > Hi, > > I want to join a DStream with some other dataset, e.g. join a click > stream with a spam ip list. I can think of two possible solutions, one > is use broadcast variable, and the other is use transform operation as > is described in the manual. > > But the problem is the spam ip list will be updated outside of the > spark streaming program, so how can it be noticed to reload the list? > > For broadcast variables, they are immutable. > > For transform operation, is it costly to reload the RDD on every > batch? If it is, and I use RDD.persist(), does it mean I need to > launch a thread to regularly unpersist it so that it can get the > updates? > > Any ideas will be appreciated. Thanks. > > -- > Jerry > > - > To unsubscribe, e-mail: user-unsubscr...@spark.apache.org > For additional commands, e-mail: user-h...@spark.apache.org > >
Re: Join DStream With Other Datasets
Hi,
After some experiments, there're three methods that work in this 'join
DStream with other dataset which is updated periodically'.
1. Create an RDD in transform operation
val words = ssc.socketTextStream("localhost", ).flatMap(_.split("_"))
val filtered = words transform { rdd =>
val spam = ssc.sparkContext.textFile("spam.txt").collect.toSet
rdd.filter(!spam(_))
}
The caveat is 'spam.txt' will be read in every batch.
2. Use variable broadcast variable...
var bc = ssc.sparkContext.broadcast(getSpam)
val filtered = words.filter(!bc.value(_))
val pool = Executors.newSingleThreadScheduledExecutor
pool.scheduleAtFixedRate(new Runnable {
def run(): Unit = {
val obc = bc
bc = ssc.sparkContext.broadcast(getSpam)
obc.unpersist
}
}, 0, 5, TimeUnit.SECONDS)
I'm surprised to come up with this solution, but I don't like var, and
the unpersist thing looks evil.
3. Use accumulator
val spam = ssc.sparkContext.accumulableCollection(getSpam.to[mutable.HashSet])
val filtered = words.filter(!spam.value(_))
def run(): Unit = {
spam.setValue(getSpam.to[mutable.HashSet])
}
Now it looks less ugly...
Anyway, I still hope there's a better solution.
On Sun, Jan 18, 2015 at 2:12 AM, Jörn Franke wrote:
> Can't you send a special event through spark streaming once the list is
> updated? So you have your normal events and a special reload event
>
> Le 17 janv. 2015 15:06, "Ji ZHANG" a écrit :
>>
>> Hi,
>>
>> I want to join a DStream with some other dataset, e.g. join a click
>> stream with a spam ip list. I can think of two possible solutions, one
>> is use broadcast variable, and the other is use transform operation as
>> is described in the manual.
>>
>> But the problem is the spam ip list will be updated outside of the
>> spark streaming program, so how can it be noticed to reload the list?
>>
>> For broadcast variables, they are immutable.
>>
>> For transform operation, is it costly to reload the RDD on every
>> batch? If it is, and I use RDD.persist(), does it mean I need to
>> launch a thread to regularly unpersist it so that it can get the
>> updates?
>>
>> Any ideas will be appreciated. Thanks.
>>
>> --
>> Jerry
>>
>> -
>> To unsubscribe, e-mail: user-unsubscr...@spark.apache.org
>> For additional commands, e-mail: user-h...@spark.apache.org
>>
>
--
Jerry
-
To unsubscribe, e-mail: user-unsubscr...@spark.apache.org
For additional commands, e-mail: user-h...@spark.apache.org
Re: Join DStream With Other Datasets
Can't you send a special event through spark streaming once the list is updated? So you have your normal events and a special reload event Le 17 janv. 2015 15:06, "Ji ZHANG" a écrit : > Hi, > > I want to join a DStream with some other dataset, e.g. join a click > stream with a spam ip list. I can think of two possible solutions, one > is use broadcast variable, and the other is use transform operation as > is described in the manual. > > But the problem is the spam ip list will be updated outside of the > spark streaming program, so how can it be noticed to reload the list? > > For broadcast variables, they are immutable. > > For transform operation, is it costly to reload the RDD on every > batch? If it is, and I use RDD.persist(), does it mean I need to > launch a thread to regularly unpersist it so that it can get the > updates? > > Any ideas will be appreciated. Thanks. > > -- > Jerry > > - > To unsubscribe, e-mail: user-unsubscr...@spark.apache.org > For additional commands, e-mail: user-h...@spark.apache.org > >
