Re: [appengine-java] Re: Get execution duration of an asynchronous urlfetch
Didier, your idea is good but can/want execute activity on a task. I need simple approach: run X async urlfetch, wait for end of execution and store execution time of each fetch. I've opened a feature request on the issue tracker: http://code.google.com/p/googleappengine/issues/detail?id=4476 Fabrizio On Sun, Jan 30, 2011 at 8:28 AM, Didier Durand durand.did...@gmail.comwrote: Hi, You're right: async url fetch doesn't seem to provide any way to measure fetch time. Then, I have a proposal: why don't you schedule a task per fetch, this task will then do a regular synchronous url fetch for which measuring will be easy. So, your original servlet / task will schedule as many tasks as you have fetches and wait via a loop of Thread.sleep() until all fetches are done and their results (incl fetch time) written somewhere (datastore / memcache) that the original servlet / task can access to complete the work. The only question though: can the application afford to launch those tasks as they will incurr some overhead : some tenths of milliseconds of cpu to schedule a task and run it + cpu time to write result to cacche or ds in order to be shareable with originator. If not acceptable, I hope it will at least give you some other ideas to follow regards didier On Jan 29, 9:50 am, Fabrizio Accatino fht...@gmail.com wrote: Hello, I'm playing with async urlfetch. My ispiration was Ikai athttp:// ikaisays.com/2010/06/29/using-asynchronous-urlfetch-on-java-ap... I run some request in parallel. All works fine. But now I'd like to get info about execution time of each request. The target URLs I call are different so the response time are very different. I read the documentation but HTTPResponse does not expose a execution duration or similar value. Any idea? Fabrizio -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.comgoogle-appengine-java%2bunsubscr...@googlegroups.com . For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en. -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
Re: [appengine-java] Re: Semaphores/ LinkedBlockingQueue on GAE for java
So, you mean polling on the database.
I wrote:
try {
for (int i=0; i100; i++) {
entity = ofy.find(ToModemInfoEntity.class, whatever);
if (entity != null) {
log.info(got data from db, do my stuff here...);
} else {
Thread.sleep(100);
}
}
}catch (Throwable th) {
th.printStackTrace();
}
It is cpu-time consuming.
It polls for about 11seconds and it takes about 1500ms of the cpu time.
It makes more than 2hours of the CPU time per natural day.
I can extend the Time.sleep(period) but it still seems unacceptable due to
CPU costs.
On Sun, Jan 30, 2011 at 8:21 AM, Didier Durand durand.did...@gmail.comwrote:
Sorry,
hit send too quicly
b) why don't you do something like this
Side reading data:
==
do {
read new data from ds;
if (new data) {
mark data as read in ds
do what you need
return;
} else {
Thread.sleep(100)
}
} until (running time near 30s)
if (no new data) {
give error message to waiting user
}
Side writing data
==
write new data to datastore (with corresponding status showing that
it's new and not read yet)
N.B: the 30s is a hard limit imposed by gae. You've to check for it
and end gracefully else your servlet will be killed by GAE.
regards
didier
On Jan 30, 8:15 am, Didier Durand durand.did...@gmail.com wrote:
Hi,
To answer your questions:
a) yes, you can say how long you waits Thread.sleep(millis) where
millis says how many milliseconds you want to wait
b) why don't you do something like this
do {
read new data from ds;
}
On Jan 29, 10:38 pm, Stephen Johnson onepagewo...@gmail.com wrote:
At the moment the Channel API is javascript only. There are a lot of
people
that would like it to be open to other languages for things just like
you
want to do. You might be able to use something like Rhino to run the
javascript in Java but not sure if that will work. You should take a
look at
XMPP, it's very simple to have the server send instant messages. I did
a
quick search for XMPP libraries in Java and here is one I found. I'm
sure
there are many others. Check outhttp://
twit88.com/blog/2009/02/17/java-xmpp-client-library/
On Sat, Jan 29, 2011 at 2:07 PM, Artur Downar
artur.dow...@googlemail.comwrote:
Thank you.
I took a brief look on channel API and it seems I it is the thing I
need.
I have a small question.
The modem device is a java embedded device and it has no public IP.
There
is no javascript on it. Only java.
Is it enough for GAE channel API to communicate with it ?
On Sat, Jan 29, 2011 at 9:49 PM, Stephen Johnson
onepagewo...@gmail.com
wrote:
Sounds like you need more of a Push style. Checkout the Channel API
or the
XMPP api.
On Sat, Jan 29, 2011 at 1:47 PM, Artur Downar
artur.dow...@googlemail.com wrote:
The external device polls for data from GAE.
It is not specified when the data arrives. To describe it more
clearly.
The device is a GSM modem device that sends an SMS on the user
request.
The user launches a web browser and writes a mobile phone number.
The
browser sends data to the GAE and the sms should be send
immediately
So I cannot specify how long I can wait in Thread.sleep().
You mention about Objectify. I use that library but I'm quite new
to it.
Does it have the mechanism that works like:
process A waits for data until data into database arrives or
timeout
expires
process B puts the data into database
process a continues processing the data inserted by process B
?
On Sat, Jan 29, 2011 at 3:59 PM, Didier Durand
durand.did...@gmail.comwrote:
Hi,
Forgot: you can use Thread.sleep() to wait (java.lang.Thread is
also
part of the JRE)
regards
didier
On Jan 29, 3:35 pm, Didier Durand durand.did...@gmail.com
wrote:
Hi,
LinkedBlokingQueue is part of JRE WhiteList:
http://code.google.com/appengine/docs/java/jrewhitelist.html. So,
you
can use it.
But, I dont see the need. Why don't you just from on the
datastore on
1 side and read from it on the other. It would be very simple
and rely
on the most basic (i.e solid) mechanism of gae. (I would
recommend
Objectify for ds read/ write)
As you have network round-trips, the read / write time will be
negligible even it can seem high compared to an in-memory
mechanism
like a Queue.
regards
didier
On Jan 29, 1:51 pm, arturad artur.dow...@googlemail.com
wrote:
In my application an embedded device (no public IP) should
connect
to
the GAE in order to obtain some data from it. The data are
provided
by
the web browser.
[appengine-java] persist generics
Hi all,
Does anyone know if it's possible to persist generic classes (with JDO, for
example)? I have a class like this:
@PersistenceCapable(identityType = IdentityType.APPLICATION, detachable =
true)
public class MyClassT extends IsSerializable implements IsSerializable {
...
}
but the JDO compiler is having a problem with recognizing T (see
transcript below).
Has anyone persisted generic classes with JDO and GAE?
Thanks,
~Owen
LOG:
30-ene-2011 12:33:07 org.datanucleus.enhancer.asm.ASMClassEnhancer enhance
GRAVE: Error thrown enhancing with ASMClassEnhancer
java.lang.IllegalStateException: Unknown type: T
at
org.datanucleus.jdo.metadata.JDOAnnotationReader.processMemberAnnotations(JDOAnnotationReader.java:1659)
at
org.datanucleus.metadata.annotations.AbstractAnnotationReader.getMetaDataForClass(AbstractAnnotationReader.java:169)
at
org.datanucleus.metadata.annotations.AnnotationManagerImpl.getMetaDataForClass(AnnotationManagerImpl.java:136)
at
org.datanucleus.metadata.MetaDataManager.loadAnnotationsForClass(MetaDataManager.java:2278)
at
org.datanucleus.jdo.metadata.JDOMetaDataManager.getMetaDataForClassInternal(JDOMetaDataManager.java:369)
at
org.datanucleus.metadata.MetaDataManager.getMetaDataForClass(MetaDataManager.java:1125)
at
org.datanucleus.enhancer.AbstractClassEnhancer.isPersistenceCapable(AbstractClassEnhancer.java:183)
at
org.datanucleus.enhancer.asm.JdoMethodAdapter.visitFieldInsn(JdoMethodAdapter.java:81)
at org.objectweb.asm.ClassReader.accept(Unknown Source)
at org.objectweb.asm.ClassReader.accept(Unknown Source)
at
org.datanucleus.enhancer.asm.ASMClassEnhancer.enhance(ASMClassEnhancer.java:355)
at
org.datanucleus.enhancer.DataNucleusEnhancer.enhanceClass(DataNucleusEnhancer.java:974)
at
org.datanucleus.enhancer.DataNucleusEnhancer.enhance(DataNucleusEnhancer.java:570)
at
org.datanucleus.enhancer.DataNucleusEnhancer.main(DataNucleusEnhancer.java:1252)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.appengine.tools.enhancer.Enhancer.execute(Enhancer.java:57)
at com.google.appengine.tools.enhancer.Enhance.init(Enhance.java:60)
at com.google.appengine.tools.enhancer.Enhance.main(Enhance.java:41)
--
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[appengine-java] Re: Semaphores/ LinkedBlockingQueue on GAE for java
Hi,
the most efficient for ofy is to get on a Long key
So, could you try again with a ofy.get() on entity with a fixed key ?
Should reduce the cpu
NB; with 2 hours / day. you're still on the gratis zone (6.5 h/day)
regards
didier
On Jan 30, 1:10 pm, Artur Downar artur.dow...@googlemail.com wrote:
So, you mean polling on the database.
I wrote:
try {
for (int i=0; i100; i++) {
entity = ofy.find(ToModemInfoEntity.class, whatever);
if (entity != null) {
log.info(got data from db, do my stuff here...);
} else {
Thread.sleep(100);
}
}
}catch (Throwable th) {
th.printStackTrace();
}
It is cpu-time consuming.
It polls for about 11seconds and it takes about 1500ms of the cpu time.
It makes more than 2hours of the CPU time per natural day.
I can extend the Time.sleep(period) but it still seems unacceptable due to
CPU costs.
On Sun, Jan 30, 2011 at 8:21 AM, Didier Durand durand.did...@gmail.comwrote:
Sorry,
hit send too quicly
b) why don't you do something like this
Side reading data:
==
do {
read new data from ds;
if (new data) {
mark data as read in ds
do what you need
return;
} else {
Thread.sleep(100)
}
} until (running time near 30s)
if (no new data) {
give error message to waiting user
}
Side writing data
==
write new data to datastore (with corresponding status showing that
it's new and not read yet)
N.B: the 30s is a hard limit imposed by gae. You've to check for it
and end gracefully else your servlet will be killed by GAE.
regards
didier
On Jan 30, 8:15 am, Didier Durand durand.did...@gmail.com wrote:
Hi,
To answer your questions:
a) yes, you can say how long you waits Thread.sleep(millis) where
millis says how many milliseconds you want to wait
b) why don't you do something like this
do {
read new data from ds;
}
On Jan 29, 10:38 pm, Stephen Johnson onepagewo...@gmail.com wrote:
At the moment the Channel API is javascript only. There are a lot of
people
that would like it to be open to other languages for things just like
you
want to do. You might be able to use something like Rhino to run the
javascript in Java but not sure if that will work. You should take a
look at
XMPP, it's very simple to have the server send instant messages. I did
a
quick search for XMPP libraries in Java and here is one I found. I'm
sure
there are many others. Check outhttp://
twit88.com/blog/2009/02/17/java-xmpp-client-library/
On Sat, Jan 29, 2011 at 2:07 PM, Artur Downar
artur.dow...@googlemail.comwrote:
Thank you.
I took a brief look on channel API and it seems I it is the thing I
need.
I have a small question.
The modem device is a java embedded device and it has no public IP.
There
is no javascript on it. Only java.
Is it enough for GAE channel API to communicate with it ?
On Sat, Jan 29, 2011 at 9:49 PM, Stephen Johnson
onepagewo...@gmail.com
wrote:
Sounds like you need more of a Push style. Checkout the Channel API
or the
XMPP api.
On Sat, Jan 29, 2011 at 1:47 PM, Artur Downar
artur.dow...@googlemail.com wrote:
The external device polls for data from GAE.
It is not specified when the data arrives. To describe it more
clearly.
The device is a GSM modem device that sends an SMS on the user
request.
The user launches a web browser and writes a mobile phone number.
The
browser sends data to the GAE and the sms should be send
immediately
So I cannot specify how long I can wait in Thread.sleep().
You mention about Objectify. I use that library but I'm quite new
to it.
Does it have the mechanism that works like:
process A waits for data until data into database arrives or
timeout
expires
process B puts the data into database
process a continues processing the data inserted by process B
?
On Sat, Jan 29, 2011 at 3:59 PM, Didier Durand
durand.did...@gmail.comwrote:
Hi,
Forgot: you can use Thread.sleep() to wait (java.lang.Thread is
also
part of the JRE)
regards
didier
On Jan 29, 3:35 pm, Didier Durand durand.did...@gmail.com
wrote:
Hi,
LinkedBlokingQueue is part of JRE WhiteList:
http://code.google.com/appengine/docs/java/jrewhitelist.html. So,
you
can use it.
But, I dont see the need. Why don't you just from on the
datastore on
1 side and read from it on the other. It would be very simple
and rely
on the most basic (i.e solid) mechanism of gae. (I would
recommend
Objectify for ds read/ write)
As you have network round-trips, the read / write time
[appengine-java] Re: Semaphores/ LinkedBlockingQueue on GAE for java
PS: you should also combine memcache + ds datastore to reduce cpu.
regards
didier
On Jan 30, 1:10 pm, Artur Downar artur.dow...@googlemail.com wrote:
So, you mean polling on the database.
I wrote:
try {
for (int i=0; i100; i++) {
entity = ofy.find(ToModemInfoEntity.class, whatever);
if (entity != null) {
log.info(got data from db, do my stuff here...);
} else {
Thread.sleep(100);
}
}
}catch (Throwable th) {
th.printStackTrace();
}
It is cpu-time consuming.
It polls for about 11seconds and it takes about 1500ms of the cpu time.
It makes more than 2hours of the CPU time per natural day.
I can extend the Time.sleep(period) but it still seems unacceptable due to
CPU costs.
On Sun, Jan 30, 2011 at 8:21 AM, Didier Durand durand.did...@gmail.comwrote:
Sorry,
hit send too quicly
b) why don't you do something like this
Side reading data:
==
do {
read new data from ds;
if (new data) {
mark data as read in ds
do what you need
return;
} else {
Thread.sleep(100)
}
} until (running time near 30s)
if (no new data) {
give error message to waiting user
}
Side writing data
==
write new data to datastore (with corresponding status showing that
it's new and not read yet)
N.B: the 30s is a hard limit imposed by gae. You've to check for it
and end gracefully else your servlet will be killed by GAE.
regards
didier
On Jan 30, 8:15 am, Didier Durand durand.did...@gmail.com wrote:
Hi,
To answer your questions:
a) yes, you can say how long you waits Thread.sleep(millis) where
millis says how many milliseconds you want to wait
b) why don't you do something like this
do {
read new data from ds;
}
On Jan 29, 10:38 pm, Stephen Johnson onepagewo...@gmail.com wrote:
At the moment the Channel API is javascript only. There are a lot of
people
that would like it to be open to other languages for things just like
you
want to do. You might be able to use something like Rhino to run the
javascript in Java but not sure if that will work. You should take a
look at
XMPP, it's very simple to have the server send instant messages. I did
a
quick search for XMPP libraries in Java and here is one I found. I'm
sure
there are many others. Check outhttp://
twit88.com/blog/2009/02/17/java-xmpp-client-library/
On Sat, Jan 29, 2011 at 2:07 PM, Artur Downar
artur.dow...@googlemail.comwrote:
Thank you.
I took a brief look on channel API and it seems I it is the thing I
need.
I have a small question.
The modem device is a java embedded device and it has no public IP.
There
is no javascript on it. Only java.
Is it enough for GAE channel API to communicate with it ?
On Sat, Jan 29, 2011 at 9:49 PM, Stephen Johnson
onepagewo...@gmail.com
wrote:
Sounds like you need more of a Push style. Checkout the Channel API
or the
XMPP api.
On Sat, Jan 29, 2011 at 1:47 PM, Artur Downar
artur.dow...@googlemail.com wrote:
The external device polls for data from GAE.
It is not specified when the data arrives. To describe it more
clearly.
The device is a GSM modem device that sends an SMS on the user
request.
The user launches a web browser and writes a mobile phone number.
The
browser sends data to the GAE and the sms should be send
immediately
So I cannot specify how long I can wait in Thread.sleep().
You mention about Objectify. I use that library but I'm quite new
to it.
Does it have the mechanism that works like:
process A waits for data until data into database arrives or
timeout
expires
process B puts the data into database
process a continues processing the data inserted by process B
?
On Sat, Jan 29, 2011 at 3:59 PM, Didier Durand
durand.did...@gmail.comwrote:
Hi,
Forgot: you can use Thread.sleep() to wait (java.lang.Thread is
also
part of the JRE)
regards
didier
On Jan 29, 3:35 pm, Didier Durand durand.did...@gmail.com
wrote:
Hi,
LinkedBlokingQueue is part of JRE WhiteList:
http://code.google.com/appengine/docs/java/jrewhitelist.html. So,
you
can use it.
But, I dont see the need. Why don't you just from on the
datastore on
1 side and read from it on the other. It would be very simple
and rely
on the most basic (i.e solid) mechanism of gae. (I would
recommend
Objectify for ds read/ write)
As you have network round-trips, the read / write time will be
negligible even it can seem high compared to an in-memory
mechanism
like a Queue.
regards
didier
On Jan 29,
[appengine-java] Re: persist generics
Why you wanna do that ? As I can see from your example, you can do MyClassPerson and also MyClassTable, but what is in common between tables and the persons ? If you have some common logic, you can use some kind of service class that could do that. -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
Re: [appengine-java] Re: Semaphores/ LinkedBlockingQueue on GAE for java
Yes, you are right.
It takes 400-600ms so it costs about an hour of the cpu time per 24hours.
It is acceptable.
I DO it following way:
MapObject, ToModemInfoEntity entity;
try {
for (int i=0; i100; i++) {
entity = ofy.get(ToModemInfoEntity.class);
if (entity != null !entity.isEmpty()) {
log.info(got data from db, do my stuff here...);
} else {
Thread.sleep(100);
}
}
}
Can I improove anything else, please ?
On Sun, Jan 30, 2011 at 1:36 PM, Didier Durand durand.did...@gmail.comwrote:
PS: you should also combine memcache + ds datastore to reduce cpu.
regards
didier
On Jan 30, 1:10 pm, Artur Downar artur.dow...@googlemail.com wrote:
So, you mean polling on the database.
I wrote:
try {
for (int i=0; i100; i++) {
entity = ofy.find(ToModemInfoEntity.class, whatever);
if (entity != null) {
log.info(got data from db, do my stuff here...);
} else {
Thread.sleep(100);
}
}
}catch (Throwable th) {
th.printStackTrace();
}
It is cpu-time consuming.
It polls for about 11seconds and it takes about 1500ms of the cpu time.
It makes more than 2hours of the CPU time per natural day.
I can extend the Time.sleep(period) but it still seems unacceptable due
to
CPU costs.
On Sun, Jan 30, 2011 at 8:21 AM, Didier Durand durand.did...@gmail.com
wrote:
Sorry,
hit send too quicly
b) why don't you do something like this
Side reading data:
==
do {
read new data from ds;
if (new data) {
mark data as read in ds
do what you need
return;
} else {
Thread.sleep(100)
}
} until (running time near 30s)
if (no new data) {
give error message to waiting user
}
Side writing data
==
write new data to datastore (with corresponding status showing that
it's new and not read yet)
N.B: the 30s is a hard limit imposed by gae. You've to check for it
and end gracefully else your servlet will be killed by GAE.
regards
didier
On Jan 30, 8:15 am, Didier Durand durand.did...@gmail.com wrote:
Hi,
To answer your questions:
a) yes, you can say how long you waits Thread.sleep(millis) where
millis says how many milliseconds you want to wait
b) why don't you do something like this
do {
read new data from ds;
}
On Jan 29, 10:38 pm, Stephen Johnson onepagewo...@gmail.com wrote:
At the moment the Channel API is javascript only. There are a lot
of
people
that would like it to be open to other languages for things just
like
you
want to do. You might be able to use something like Rhino to run
the
javascript in Java but not sure if that will work. You should take
a
look at
XMPP, it's very simple to have the server send instant messages. I
did
a
quick search for XMPP libraries in Java and here is one I found.
I'm
sure
there are many others. Check outhttp://
twit88.com/blog/2009/02/17/java-xmpp-client-library/
On Sat, Jan 29, 2011 at 2:07 PM, Artur Downar
artur.dow...@googlemail.comwrote:
Thank you.
I took a brief look on channel API and it seems I it is the thing
I
need.
I have a small question.
The modem device is a java embedded device and it has no public
IP.
There
is no javascript on it. Only java.
Is it enough for GAE channel API to communicate with it ?
On Sat, Jan 29, 2011 at 9:49 PM, Stephen Johnson
onepagewo...@gmail.com
wrote:
Sounds like you need more of a Push style. Checkout the Channel
API
or the
XMPP api.
On Sat, Jan 29, 2011 at 1:47 PM, Artur Downar
artur.dow...@googlemail.com wrote:
The external device polls for data from GAE.
It is not specified when the data arrives. To describe it more
clearly.
The device is a GSM modem device that sends an SMS on the user
request.
The user launches a web browser and writes a mobile phone
number.
The
browser sends data to the GAE and the sms should be send
immediately
So I cannot specify how long I can wait in Thread.sleep().
You mention about Objectify. I use that library but I'm quite
new
to it.
Does it have the mechanism that works like:
process A waits for data until data into database arrives or
timeout
expires
process B puts the data into database
process a continues processing the data inserted by process B
?
On Sat, Jan 29, 2011 at 3:59 PM, Didier Durand
durand.did...@gmail.comwrote:
Hi,
Forgot: you
Re: [appengine-java] Re: Semaphores/ LinkedBlockingQueue on GAE for java
If where you have specified log.info(do your stuff here) you intend to
send data back to the client and then loop again and wait for more data I
think you are going to be disappointed. I don't believe any data will be
sent back to the client until your servlet completes. So you'll have to
re-establish a connection every time data gets sent back down.
On Sun, Jan 30, 2011 at 11:20 AM, Artur Downar
artur.dow...@googlemail.comwrote:
Yes, you are right.
It takes 400-600ms so it costs about an hour of the cpu time per 24hours.
It is acceptable.
I DO it following way:
MapObject, ToModemInfoEntity entity;
try {
for (int i=0; i100; i++) {
entity = ofy.get(ToModemInfoEntity.class);
if (entity != null !entity.isEmpty()) {
log.info(got data from db, do my stuff here...);
} else {
Thread.sleep(100);
}
}
}
Can I improove anything else, please ?
On Sun, Jan 30, 2011 at 1:36 PM, Didier Durand durand.did...@gmail.comwrote:
PS: you should also combine memcache + ds datastore to reduce cpu.
regards
didier
On Jan 30, 1:10 pm, Artur Downar artur.dow...@googlemail.com wrote:
So, you mean polling on the database.
I wrote:
try {
for (int i=0; i100; i++) {
entity = ofy.find(ToModemInfoEntity.class, whatever);
if (entity != null) {
log.info(got data from db, do my stuff here...);
} else {
Thread.sleep(100);
}
}
}catch (Throwable th) {
th.printStackTrace();
}
It is cpu-time consuming.
It polls for about 11seconds and it takes about 1500ms of the cpu time.
It makes more than 2hours of the CPU time per natural day.
I can extend the Time.sleep(period) but it still seems unacceptable due
to
CPU costs.
On Sun, Jan 30, 2011 at 8:21 AM, Didier Durand durand.did...@gmail.com
wrote:
Sorry,
hit send too quicly
b) why don't you do something like this
Side reading data:
==
do {
read new data from ds;
if (new data) {
mark data as read in ds
do what you need
return;
} else {
Thread.sleep(100)
}
} until (running time near 30s)
if (no new data) {
give error message to waiting user
}
Side writing data
==
write new data to datastore (with corresponding status showing that
it's new and not read yet)
N.B: the 30s is a hard limit imposed by gae. You've to check for it
and end gracefully else your servlet will be killed by GAE.
regards
didier
On Jan 30, 8:15 am, Didier Durand durand.did...@gmail.com wrote:
Hi,
To answer your questions:
a) yes, you can say how long you waits Thread.sleep(millis) where
millis says how many milliseconds you want to wait
b) why don't you do something like this
do {
read new data from ds;
}
On Jan 29, 10:38 pm, Stephen Johnson onepagewo...@gmail.com
wrote:
At the moment the Channel API is javascript only. There are a lot
of
people
that would like it to be open to other languages for things just
like
you
want to do. You might be able to use something like Rhino to run
the
javascript in Java but not sure if that will work. You should take
a
look at
XMPP, it's very simple to have the server send instant messages. I
did
a
quick search for XMPP libraries in Java and here is one I found.
I'm
sure
there are many others. Check outhttp://
twit88.com/blog/2009/02/17/java-xmpp-client-library/
On Sat, Jan 29, 2011 at 2:07 PM, Artur Downar
artur.dow...@googlemail.comwrote:
Thank you.
I took a brief look on channel API and it seems I it is the
thing I
need.
I have a small question.
The modem device is a java embedded device and it has no public
IP.
There
is no javascript on it. Only java.
Is it enough for GAE channel API to communicate with it ?
On Sat, Jan 29, 2011 at 9:49 PM, Stephen Johnson
onepagewo...@gmail.com
wrote:
Sounds like you need more of a Push style. Checkout the Channel
API
or the
XMPP api.
On Sat, Jan 29, 2011 at 1:47 PM, Artur Downar
artur.dow...@googlemail.com wrote:
The external device polls for data from GAE.
It is not specified when the data arrives. To describe it more
clearly.
The device is a GSM modem device that sends an SMS on the user
request.
The user launches a web browser and writes a mobile phone
number.
The
browser sends data to the GAE and the sms should be send
immediately
So I cannot specify how long I can wait in Thread.sleep().
You mention
[appengine-java] Re: OAuth with a custom domain
Anyone have any experience with authenticating non gmail.com google accounuts with GAE OAuth? On Jan 19, 10:30 pm, Eurig Jones eurigjo...@gmail.com wrote: Hi. I have an android app which has a GAE backend and validates its users using OAuth. It does not seem to validate users with a custom google domain. What do I need to do to get this to work? Thanks!Eurig -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
Re: [appengine-java] Re: Semaphores/ LinkedBlockingQueue on GAE for java
Yes I know it. I have to fill the response end return from the doGet (req,
resp) method.
I'm very sad because of the 1hour of wasted CPU time. It is the very basic
functionality, but it would consume so much...
I have to investigate both the channel API and the XMPP before I choose the
solution.
Will see if it would be possible to write my own not javascript library to
use the channel API and how much time it will take.
I guess I would like to avoid the XMPP because my modem processor is quite
weak. have to make some investigation if it handles the requirements.
On Sun, Jan 30, 2011 at 7:30 PM, Stephen Johnson onepagewo...@gmail.comwrote:
If where you have specified log.info(do your stuff here) you intend to
send data back to the client and then loop again and wait for more data I
think you are going to be disappointed. I don't believe any data will be
sent back to the client until your servlet completes. So you'll have to
re-establish a connection every time data gets sent back down.
On Sun, Jan 30, 2011 at 11:20 AM, Artur Downar
artur.dow...@googlemail.com wrote:
Yes, you are right.
It takes 400-600ms so it costs about an hour of the cpu time per 24hours.
It is acceptable.
I DO it following way:
MapObject, ToModemInfoEntity entity;
try {
for (int i=0; i100; i++) {
entity = ofy.get(ToModemInfoEntity.class);
if (entity != null !entity.isEmpty()) {
log.info(got data from db, do my stuff here...);
} else {
Thread.sleep(100);
}
}
}
Can I improove anything else, please ?
On Sun, Jan 30, 2011 at 1:36 PM, Didier Durand
durand.did...@gmail.comwrote:
PS: you should also combine memcache + ds datastore to reduce cpu.
regards
didier
On Jan 30, 1:10 pm, Artur Downar artur.dow...@googlemail.com wrote:
So, you mean polling on the database.
I wrote:
try {
for (int i=0; i100; i++) {
entity = ofy.find(ToModemInfoEntity.class, whatever);
if (entity != null) {
log.info(got data from db, do my stuff here...);
} else {
Thread.sleep(100);
}
}
}catch (Throwable th) {
th.printStackTrace();
}
It is cpu-time consuming.
It polls for about 11seconds and it takes about 1500ms of the cpu time.
It makes more than 2hours of the CPU time per natural day.
I can extend the Time.sleep(period) but it still seems unacceptable due
to
CPU costs.
On Sun, Jan 30, 2011 at 8:21 AM, Didier Durand
durand.did...@gmail.comwrote:
Sorry,
hit send too quicly
b) why don't you do something like this
Side reading data:
==
do {
read new data from ds;
if (new data) {
mark data as read in ds
do what you need
return;
} else {
Thread.sleep(100)
}
} until (running time near 30s)
if (no new data) {
give error message to waiting user
}
Side writing data
==
write new data to datastore (with corresponding status showing that
it's new and not read yet)
N.B: the 30s is a hard limit imposed by gae. You've to check for it
and end gracefully else your servlet will be killed by GAE.
regards
didier
On Jan 30, 8:15 am, Didier Durand durand.did...@gmail.com wrote:
Hi,
To answer your questions:
a) yes, you can say how long you waits Thread.sleep(millis) where
millis says how many milliseconds you want to wait
b) why don't you do something like this
do {
read new data from ds;
}
On Jan 29, 10:38 pm, Stephen Johnson onepagewo...@gmail.com
wrote:
At the moment the Channel API is javascript only. There are a lot
of
people
that would like it to be open to other languages for things just
like
you
want to do. You might be able to use something like Rhino to run
the
javascript in Java but not sure if that will work. You should
take a
look at
XMPP, it's very simple to have the server send instant messages.
I did
a
quick search for XMPP libraries in Java and here is one I found.
I'm
sure
there are many others. Check outhttp://
twit88.com/blog/2009/02/17/java-xmpp-client-library/
On Sat, Jan 29, 2011 at 2:07 PM, Artur Downar
artur.dow...@googlemail.comwrote:
Thank you.
I took a brief look on channel API and it seems I it is the
thing I
need.
I have a small question.
The modem device is a java embedded device and it has no public
IP.
There
is no javascript on it. Only java.
Is it enough for GAE channel API to communicate with it ?
On Sat, Jan 29, 2011 at 9:49 PM, Stephen Johnson
onepagewo...@gmail.com
[appengine-java] Powered by Google Technologies
Wanted to share our project called CitySale.ca which is built entirely on the Google stack: Google APIs - App Engine, GWT, Maps, Fusion Tables, Geocoding, Places, Search, ... Google Tools - Analytics, DoubleClick, Webmaster The GWT Client and the App Engine based server are also deeply integrated with Facebook APIs. It is a bit scary to completely rely on a single company (Google) for all your technology/infrastructure needs, but for us the benefits outweigh this concern! Would be great to get some feedback and if I would be happy to answer any questions about how this service was built. p.s. if you are from Canada, we hope you would actually sign up and use the service too :) the url is http://www.citysale.ca Thanks, Michael Weinberg -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
[appengine-java] Uploading photos from Android
Hello, I have an Android application and I want to upload photos to my appEngine. I send the photo using a image/jpeg content-type and a POST request. However, the only code that I've found needs multipart/form-data or multipart/mixed : ServletFileUpload upload = new ServletFileUpload(); FileItemIterator iter = upload.getItemIterator(req); FileItemStream imageItem = iter.next(); InputStream imgStream = imageItem.openStream(); Blob imageBlob = new Blob(IOUtils.toByteArray(imgStream)); Do you have a working code or another solution ? Thanks -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
Re: [appengine-java] Just getting started with Datastore
Thanks for the feedback. I am willing to try the low-level API first and that's what I thought I was doing but could not figure out (and am still confused about) how to initially define data. For example I want to have a persistent entity with two properties of type string and one numerical property. When I use this bulkloader tool it is storing all the data as string, so maybe my problem is just learning how to use this tool to load data (which I definitely want to do). Thanks. -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
Re: [appengine-java] Re: Prerelease 1.3.4 SDK ready for download
Hi John Brennan, Just saw your reply, when I was searching for this issue to quote in the following reddit thread.. http://www.reddit.com/r/AppEngine/comments/fbwkz/oauth_with_gae_and_custom_google_domains/ Just checked again now and the issue seems to have been fixed. That is, I am now able to login with both the Google Apps user account r...@my-google-apps-domain.com and a Google Account created with the same email-id (both with diff passwords), by using the appropriate login options in my Google App Engine based CRM app http://crm.ifreetools.com/. Hope it is fixed for you too. On a related note, this must have been fixed at least before Jan 18, 2011 as I have now started getting signups from Google Accounts having yahoo / hotmail email-ids, which had stopped after I had moved to federated login, due to this issue. Regards, R.Rajkumar On Wed, Dec 8, 2010 at 5:43 PM, John Brennan jbren...@connectit.ie wrote: Rajkumar Radhakrishnan r.rajkumar@... writes: Thanks for enquiring, Ikai. Was held up implementing some features - including integrating OpenId support - that I missed reading the groups' emails for a few days. Regarding snags.. except when I try to login with a Google Account created using a Google Apps email-id, everything works fine. Details : When users login using normal Google Accounts and normal Google Apps user accounts, by providing the domain name, there are no issues. But, when one has a Google Apps user account with email id u...@myappsdomain.com and had created a Google Account providing this email-id. Then, logging in with this Google Account (instead of Google Apps account) an Internal Server Error occurs.. Error: Server Error The server encountered an error and could not complete your request. If the problem persists, please report your problem and mention this error message and the query that caused it. Hi R.Rajkumar, I'm having the exact same problem. Did you ever resolve the issue? I'm able to use a Google Account, created using a Google Apps email, to login into other sample applications on Appengine using federated log in so there must be a way to get around it. Thanks John Brennan -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.comgoogle-appengine-java%2bunsubscr...@googlegroups.com . For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en. -- http://crm.ifreetools.com -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
