Up until last week I have been running my GWT/AppEngine app with no problems using java.io.Serializable and implements Serializable on my classes in RPC calls.
Now I get this error on appengine: Type 'com.foobar.web.shared.RPCDTOclass' was not assignable to 'com.google.gwt.user.client.rpc.IsSerializable' and did not have a custom field serializer.
I still have the implements Serializable. If I fix/change that class and make it com.google.gwt.user.client.rpc.IsSerializable it works for that class but I get the same error for other classes used in RPC. I only have Strings in some of them, so it isn't that I have types that I can't serialize.
I don't see anyone else having this problem so I must have made some type of change that is causing it, but I don't know what. The error shows up on AppEngine, so I think it must be an appengine problem?
Thanks
Adding an example
public class UserLogInDTO implements IsSerializable {
private String Email;
private String PasswordHash;
public UserLogInDTO(){}
public UserLogInDTO(String email, String passwordhash){
setEmail(email);
setPasswordHash(passwordhash);
}
public void Set(String email, String passwordhash){
this.setEmail(email);
this.setPasswordHash(passwordhash);
}
/**
* #return the email
*/
public String getEmail() {
return Email;
}
/**
* #param email the email to set
*/
public void setEmail(String email) {
Email = email.toLowerCase();
}
/**
* #return the passwordHash
*/
public String getPasswordHash() {
return PasswordHash;
}
/**
* #param passwordHash the passwordHash to set
*/
public void setPasswordHash(String passwordHash) {
PasswordHash = passwordHash;
}
}
If I have implements IsSerializable it works, if implements Serializable it used to work but now doesn't. I am using 1.7.2 SDK for AppEngine 2.4.0 for GWT
Related
I am implementing Circuit breaker using Hystrix in my Spring boot application, my code is something like below:
#service
public class MyServiceHandler {
#HystrixCommand(fallbackMethod="fallback")
public String callService() {
// if(remote service is not reachable
// throw ServiceException
}
public String fallback() {
// return default response
}
}
// In application.properties, I have below properties defined:
hystrix.command.default.execution.isolation.thread.timeoutInMilliseconds=10000
hystrix.command.default.circuitBreaker.requestVolumeThreshold=3
hystrix.command.default.circuitBreaker.sleepWindowInMilliseconds=30000
hystrix.threadpool.default.coreSize=4
hystrix.threadpool.default.metrics.rollingStats.timeInMilliseconds=200000
I see that the fallback() is getting called with each failure of callService(). However, the circuit is not opening after 3 failures. After 3 failures, I was expecting that it will directly call fallback() and skip callService(). But this is not happening. Can someone advise what I am doing wrong here?
Thanks,
B Jagan
Edited on 26th July to add more details below:
Below is the actual code. I played a bit further with this. I see that the Circuit opens as expected on repeated failured when I call the remote service directly in the RegistrationHystrix.registerSeller() method. But, when I wrap the remote service call within Spring retry template, it keeps going into fallback method, but circuit never opens.
#Service
public class RegistrationHystrix {
Logger logger = LoggerFactory.getLogger(RegistrationHystrix.class);
private RestTemplate restTemplate;
private RetryTemplate retryTemplate;
public RegistrationHystrix(RestTemplate restTemplate) {
this.restTemplate = restTemplate;
retryTemplate = new RetryTemplate();
FixedBackOffPolicy fixedBackOffPolicy = new FixedBackOffPolicy();
fixedBackOffPolicy.setBackOffPeriod(1000l);
retryTemplate.setBackOffPolicy(fixedBackOffPolicy);
SimpleRetryPolicy retryPolicy = new SimpleRetryPolicy();
retryPolicy.setMaxAttempts(3);
retryTemplate.setRetryPolicy(retryPolicy);
}
#HystrixCommand(fallbackMethod = "fallbackForRegisterSeller", commandKey = "ordermanagement")
public String registerSeller(SellerDto sellerDto) throws Exception {
String response = retryTemplate.execute(new RetryCallback<String, Exception>() {
#Override
public String doWithRetry(RetryContext context) {
logger.info(String.format("Retry count %d", context.getRetryCount()));
return restTemplate.postForObject("/addSeller", sellerDto, String.class);
}
});
return response;
}
public List<SellerDto> getSellersList() {
return restTemplate.getForObject("/sellersList", List.class);
}
public String fallbackForRegisterSeller(SellerDto sellerDto, Throwable t) {
logger.error("Inside fall back, cause - {}", t.toString());
return "Inside fallback method. Some error occured while calling service for seller registration";
}
}
Below is the service class which in turn calls the above Hystrix wrapped service. This class in turn is invoked by a controller.
#Service
public class RegistrationServiceImpl implements RegistrationService {
Logger logger = LoggerFactory.getLogger(RegistrationServiceImpl.class);
private RegistrationHystrix registrationHystrix;
public RegistrationServiceImpl(RegistrationHystrix registrationHystrix) {
this.registrationHystrix = registrationHystrix;
}
#Override
public String registerSeller(SellerDto sellerDto) throws Exception {
long start = System.currentTimeMillis();
String registerSeller = registrationHystrix.registerSeller(sellerDto);
logger.info("add seller call returned in - {}", System.currentTimeMillis() - start);
return registerSeller;
}
So, I am trying to understand why the Circuit breaker is not working as expected when using it along with Spring RetryTemplate.
You should be using metrics.healthSnapshot.intervalInMilliseconds while testing. I guess you are executing all 3 request within default 500 ms and hence the circuit isn't getting open. You can either decrease this interval or you may put a sleep between the 3 requests.
The Intro
Hi there, I am doing a module on Go AppEngine and I have problems reading some models, that have nested models inside. The model is Party, and what I want is Permissions. But, when I get Party from datastore, Permissions struct field is of type string.
//And when I do fmt.Println(party.Permissions) show this:
%!(EXTRA string=jjrz�5878654076715008 *��jjrzshowOnMessages
*zcanInviteAssistants *zcanInviteOrganizers *z canEditEvent
*zroleName * organizerzisAdmin *�z�4709220381360128
*��jjrzshowOnMessages *zcanInviteAssistants *zcanInviteOrganizers
*z canEditEvent *zroleName *ownerzisAdmin *��
What is that string? There is a way to get the original struct?
The Models
Go
type Party struct {
Name string `datastore:"name"`
Permissions string `datastore:"permissions"`
}
type PartyPermission struct {
isAdmin bool
canInviteOrganizers bool
canInviteAssistants bool
canEditParty bool
showOnMessages bool
roleName string
}
Java
#Entity
public class Party implements Cloneable, Serializable {
#Id
private Long id;
private String name;
private Map<String, PartyPermission> permissions;
// constructor ...
// getters, setters, etc
}
public class PartyPermission implements Serializable {
private static final long serialVersionUID = 3019266092062869643L;
private boolean isAdmin;
private boolean canInviteOrganizers;
private boolean canInviteAssistants;
private boolean canEditEvent;
private boolean showsOnMessages;
private String roleName;
// constructor
// getters, setters, etc
}
What I've tried
I started with go, on monday 10, and I don't recognize what could be that string. I think that maybe that string was an interface and I could convert that string to an interface, and then to what I really wish, map[string]PartyPermission. So, reflection:
func (p *Party) GetPermissions() (map[string]PartyPermission) {
iPermissions := reflect.ValueOf(p.Permissions).Interface()
return iPermissions.(map[string]PartyPermission)
}
That compiles great, but Go said that string couldn't be converted to another thing. Something like:
interface conversion: interface is string, not map[string]packName.PartyPermission
Thanks for your time.
You can't, you have to create a decoder for that format.
You could use json or something.
I am running a mapreduce job over 50 million User records.
For each user I read two other Datastore entities and then stream stats for each player to bigquery.
My first dry run (with streaming to bigquery disabled) failed with the following stacktrace.
/_ah/pipeline/handleTask
com.google.appengine.tools.cloudstorage.NonRetriableException: com.google.apphosting.api.ApiProxy$RequestTooLargeException: The request to API call datastore_v3.Put() was too large.
at com.google.appengine.tools.cloudstorage.RetryHelper.doRetry(RetryHelper.java:121)
at com.google.appengine.tools.cloudstorage.RetryHelper.runWithRetries(RetryHelper.java:166)
at com.google.appengine.tools.cloudstorage.RetryHelper.runWithRetries(RetryHelper.java:157)
at com.google.appengine.tools.pipeline.impl.backend.AppEngineBackEnd.tryFiveTimes(AppEngineBackEnd.java:196)
at com.google.appengine.tools.pipeline.impl.backend.AppEngineBackEnd.saveWithJobStateCheck(AppEngineBackEnd.java:236)
I have googled this error and the only thing I find is related to that the Mapper is too big to be serialized but our Mapper has no data at all.
/**
* Adds stats for a player via streaming api.
*/
public class PlayerStatsMapper extends Mapper<Entity, Void, Void> {
private static Logger log = Logger.getLogger(PlayerStatsMapper.class.getName());
private static final long serialVersionUID = 1L;
private String dataset;
private String table;
private transient GbqUtils gbq;
public PlayerStatsMapper(String dataset, String table) {
gbq = Davinci.getComponent(GbqUtils.class);
this.dataset = dataset;
this.table = table;
}
private void readObject(java.io.ObjectInputStream in) throws IOException, ClassNotFoundException {
in.defaultReadObject();
log.info("IOC reinitating due to deserialization.");
gbq = Davinci.getComponent(GbqUtils.class);
}
#Override
public void beginShard() {
}
#Override
public void endShard() {
}
#Override
public void map(Entity value) {
if (!value.getKind().equals("User")) {
log.severe("Expected a User but got a " + value.getKind());
return;
}
User user = new User(1, value);
List<Map<String, Object>> rows = new LinkedList<Map<String, Object>>();
List<PlayerStats> playerStats = readPlayerStats(user.getUserId());
addRankings(user.getUserId(), playerStats);
for (PlayerStats ps : playerStats) {
rows.add(ps.asMap());
}
// if (rows.size() > 0)
// gbq.insert(dataset, table, rows);
}
.... private methods only
}
The maprecuce job is started with this code
MapReduceSettings settings = new MapReduceSettings().setWorkerQueueName("mrworker");
settings.setBucketName(gae.getAppName() + "-playerstats");
// #formatter:off <I, K, V, O, R>
MapReduceSpecification<Entity, Void, Void, Void, Void> spec =
MapReduceSpecification.of("Enque player stats",
new DatastoreInput("User", shardCountMappers),
new PlayerStatsMapper(dataset, "playerstats"),
Marshallers.getVoidMarshaller(),
Marshallers.getVoidMarshaller(),
NoReducer.<Void, Void, Void> create(),
NoOutput.<Void, Void> create(1));
// #formatter:on
String jobId = MapReduceJob.start(spec, settings);
Well I solved this by backing to appengine-mapreduce-0.2.jar which was the one we had used before. The one used above was appengine-mapreduce-0.5.jar which actually turned out not to work for us.
When backing to 0.2 the console _ah/pipiline/list started to work again as well!
Anyone else that have encountered similar problem with 0.5?
I am using resteasy, and till now I am just sending and receiving string as parameters and every thing was OK, but now I want to send a complex object ( List<Map<String, ObjectVal>> ) as one of my parameters. My objectVal class has two simple field ( id and value, with getters and setters).
I can find different question and answers for sending objects as parameters but all of them are missing something and not useful for me.
here is my functions with a simple string parameter
#GET
#Path("/isUserAuthorizedToDocument")
public Response isUserAuthorizedToDocumentService(
#QueryParam("userID") String userID){
.............
.............
}
and the client
private ClientRequest req =new ClientRequest(....url with path and ....)
req.queryParameter("userID", user.getUserId());
ClientResponse<Boolean> response = req.get(Boolean.class);
Now I want to send a parameter from my client in the form of List<Map<String,ObjectVal>> and recieve it in my rest function.
My ObjectVal class
#XmlRootElement(name = "objectValueDTO")
public class ObjectValueDTO implements Serializable {
/**
* Id for this class
*/
private static final long serialVersionUID = 164186789404269392L;
// Id on object type
private String objectTypeID = "";
// Selection
private String value = "";
/** Getter and Setters */
#XmlElement
public String getObjectTypeID() {
return objectTypeID;
}
public void setObjectTypeID(String objectTypeID) {
this.objectTypeID = objectTypeID;
}
#XmlElement
public String getValue() {
return value;
}
public void setValue(String value) {
this.value = value;
}
}
any help will be appreciated
I may be niave on this. But when you have to send complex parameters, you need to use PUT and send the parameters in the request.
I have a method to save a new object in an EJB bean. This method is called, without error, but nothing changes in the database. I can't understand why.
Here is the code:
#Stateless(name = "Ar", mappedName = "ManagementBean")
public class ManagementBean implements IManagementBeanLocal, IManagementBeanRemote {
...
#Override
public int storeRawSms(String raw, String requestUid, String text, String service, boolean correctlyAnalysed, Date receivedTimestamp,
boolean toBeAnalysed, String phoneNumber) {
// Get phone number, create if it dosn't exist
PhoneNumber pn = getOrCreatePhoneNumberPrivate(phoneNumber);
// Create rawSMS
RawSms rawSms = new RawSms(raw, requestUid, text, service, correctlyAnalysed, receivedTimestamp, toBeAnalysed, pn);
// Store and return result
em.persist(rawSms);
int result = rawSms.getId();
em.flush();
em.clear();
return result;
}
...
And the caller:
#PersistenceContext private EntityManager em;
...
int rawSmsIs = bean.storeRawSms(raw, requestUid, message, service, false, new Date(), true, sender);
Do you have an idea?
I see that you inject a reference to the EntityManager in the client (not sure why), but I don't see it in the session bean (maybe simply because you did not include the line in your message). Is it possible that you forgot to use the annotation #PersistenceContext in your stateless session bean?
Also, be careful: depending on the JPA implementation you are using and the generation strategy for the ids, you should call flush() before calling getId(). Indeed, if you let the DB generate your IDs, then you need a flush() to have this happen before the method returns the value.
Thanks, the prposed solution worked!
I use the container-managed transactions like this:
#Stateless(name = "Ar", mappedName = "ManagementBean")
#TransactionManagement(TransactionManagementType.CONTAINER)
public class ManagementBean implements IManagementBeanLocal, IManagementBeanRemote {
....
#Override
#TransactionAttribute(TransactionAttributeType.REQUIRES_NEW)
public int storeRawSms(String raw, String requestUid, String text, String service, boolean correctlyAnalysed, Date receivedTimestamp, boolean toBeAnalysed, String phoneNumber) {
....
Thanks again!
It seems that your transaction never commited, so try changing transaction management:
#Stateless(name = "Ar", mappedName = "ManagementBean")
#TransactionManagement(TransactionManagementType.BEAN)
public class ManagementBean implements IManagementBeanLocal, IManagementBeanRemote {
#Resource
private UserTransaction utx;
#Override
public int storeRawSms(..) {
try {
utx.begin();
..
em.persist(rawSms);
int result = rawSms.getId();
utx.commit();
}
catch(Exception ex) {
//EXCEPTION HANDLING
utx.rollback();
}
}
}