I am using Zipkin with Spring Sleuth to display traces. When I use it locally, http://localhost:9411/zipkin/dependency/ displays a nicely created graph of dependencies within the eco-system. Sometimes, backends from outside that eco-system get called and those are not displayed in that graph. Is it possible to annotate a call (let's assume RestTemplate and Feign clients) to such an external system so Zipkin would actually draw that dependency? If it's possible, what do I have to do?
This would be my baseline of code:
#Bean
RestTemplate restTemplate() {
return new RestTemplate();
}
#RequestMapping("/")
public String callExternalBackend() {
return restTemplate.getForObject("https://httpbin.org/get", String.class);
}
Somewhere I would like to type httpbin so this call gets drawn in the dependency-graph of Zipkin.
Thank you!
// Edit based on current solution
I'm using Spring Cloud Finchley and added the following line before restTemplate's call:
#RequestMapping("/")
public String callBackend() {
spanCustomizer.tag("peer.service", "httpbin");
return restTemplate.getForObject("https://httpbin.org/get", String.class);
}
I simply inject SpanCustomizer in this class. The Span is sent to Zipkin and I see the tag is set:
Unfortunately, it is not drawn in the dependencies-view. Is there anything else I need to configure, maybe in Zipkin rather than in Sleuth?
EDGWARE
Have you read the documentation? If you use Spring Cloud Sleuth in Edgware version if you read the Sleuth section you would find this piece of the documentation https://cloud.spring.io/spring-cloud-static/Edgware.SR3/single/spring-cloud.html#_custom_sa_tag_in_zipkin
Let me copy that for you
54.5 Custom SA tag in Zipkin Sometimes you want to create a manual Span that will wrap a call to an external service which is not
instrumented. What you can do is to create a span with the
peer.service tag that will contain a value of the service that you
want to call. Below you can see an example of a call to Redis that is
wrapped in such a span.
org.springframework.cloud.sleuth.Span newSpan = tracer.createSpan("redis");
try {
newSpan.tag("redis.op", "get");
newSpan.tag("lc", "redis");
newSpan.logEvent(org.springframework.cloud.sleuth.Span.CLIENT_SEND);
// call redis service e.g
// return (SomeObj) redisTemplate.opsForHash().get("MYHASH", someObjKey);
} finally {
newSpan.tag("peer.service", "redisService");
newSpan.tag("peer.ipv4", "1.2.3.4");
newSpan.tag("peer.port", "1234");
newSpan.logEvent(org.springframework.cloud.sleuth.Span.CLIENT_RECV);
tracer.close(newSpan);
}
[Important] Important Remember not to add both peer.service tag and
the SA tag! You have to add only peer.service.
FINCHLEY
The SA tag will not work for Finchley. You have to do it in the following manner using the remoteEndpoint on the span.
Span span = tracer.newTrace().name("redis");
span.remoteEndpoint(Endpoint.newBuilder().serviceName("redis").build());
span.kind(CLIENT);
try(SpanInScope ws = tracer.withSpanInScope(span.start())) {
// add any tags / annotations on the span
// return (SomeObj) redisTemplate.opsForHash().get("MYHASH", someObjKey);
} finally {
span.finish();
}
Related
What I want: I'd like to move content from one ContentStore (regular) to another ContentStore (e.g. an archive) with Spring-Content version 1.2.7.
What I did is this (and it does work at least with DefaultFilesystemStoreImpls):
Creating two ContentStores like this:
#Bean(name = "mytmpfsstore1")
public ContentStore<File, String> getFileContentStore1() {
FileSystemResourceLoader loader = new FileSystemResourceLoader(".\\tmpstore1");
PlacementService placementService = new PlacementServiceImpl();
return new DefaultFilesystemStoreImpl<File, String>(loader, placementService, new FileServiceImpl());
}
Moving content from one ContentStore to another like this:
Optional<File> fileEntity = filesRepo.findById(id);
if (fileEntity.isPresent()) {
Resource resource = regularContentStore.getResource(fileEntity.get());
archiveContentStore.setContent(fileEntity.get(), resource);
filesRepo.save(fileEntity.get());
if (resource instanceof DeletableResource) {
((DeletableResource) resource).delete();
}
}
Question: Is this the intended way of moving (/archiving) content with Spring-Content or is there a more elegant / more convenient / more intended way of moving/archiving files (especially from filesystem to S3 and back again)?
Spring Content doesn't provide any magic here. I try to keep the API fairly low-level and this use case, whilst valid, is a little too granular.
So, ultimately you have to build the "archiving" yourself and at the end of the day copy the content from one store to another as you are doing.
A couple of comments/pointers:
Not sure why you instantiated mytmpfsstore1 yourself. If you have file storage and s3 storage you can just make your storage interfaces extend FileSystemContentStore and S3ContentStore respectively and let the framework instantiate them for you; i.e.
public interface MyTmpFsStore extends FileSystemContentStore {}
public interface MyS3store extends S3ContentStore()
You can then wire these two beans into your 'archive' code. Assuming that is a controller, something like:
#RequestMapping(...) public void archive(MyTmpFsStore fsStore, S3ContentStore s3Store { ... }
where you do your copy operation.
ContentStore extends AssociativeStore and there are a few different APIs for setting/unsetting content. Resource-based or InputStream. They all achieve the same objective at the end of the day. You could just have easily used getContent instead of getResource and unsetContent instead of delete.
The 'archive' code probably needs to be in a #Transactional so the archive operation is atomic.
I'm working on a blazor server-side project and I have a component that gets passed a model (pickedWeek) as a parameter. I can use the model fine in-line with the html, but OnInitializedAsync always thinks that the model is null.
I have passed native types in as parameters, from the Page into a component, this way without an issue. I use a NullWeek as a default parameter, so the number getting used in OnInitializedAsync only ever appears to be from the NullWeek. In case this is related, there is a sibling component that is returning the Week model to the Page through an .InvokeAsync call, where StateHasChanged() is being called after the update. It appears that the new Week is getting updated on the problem component, but that OnInitializeAsync() either doesn't see it, or just never fires again- which maybe is my problem, but I didn't think it worked that way.
For instance, the below code will always show "FAILURE" but it will show the correct Week.Number. Code below:
<div>#pickedWeek.Number</div>
#if(dataFromService != null)
{
<div>SUCCESS</div>
}
else
{
<div>FAILURE</div>
}
#code{
[Parameter]
public Week pickedWeek { get; set; }
protected IEnumerable<AnotherModel> dataFromService { get; set; }
protected override async Task OnInitializedAsync()
{
if (pickedWeek.Number > 0)
{
dataFromService = await _injectedService.MakeACall(pickedWeek.Id);
}
}
}
#robsta has this correct in the comments, you can use OnParametersSet for this. Then, you will run into another issue, in that each rerender will set your parameters again and generate another call to your service. I've gotten around this by using a flag field along with the the OnParametersSet method. Give this a shot and report back.
private bool firstRender = true;
protected override async Task OnParametersSetAsync()
{
if (pickedWeek.Number > 0 && firstRender)
{
dataFromService = await _injectedService.MakeACall(pickedWeek.Id);
firstRender = false;
// MAYBE call this if it doesn't work without
StateHasChanged();
}
}
Another alternative is to use the OnAfterRender override, which supplies a firstRender bool in the the method signature, and you can do similar logic. I tend to prefer the first way though, as this second way allows it to render, THEN sets the value of your list, THEN causes another rerender, which seems like more chatter than is needed to me. However if your task is long running, use this second version and build up a loading message to display while the list is null, and another to display if the service call fails. "FAILURE" is a bit misleading as you have it as it's being displayed before the call completes.
I've also found that a call to await Task.Delay(1); placed before your service call can be useful in that it breaks the UI thread loose from the service call awaiter and allows your app to render in a loading state until the data comes back.
I have a widget with list of last news, how to cache only widget output?
OutputCache module caches whole page and for anonymous users, but in fact I need to cache only one shape output.
What solution can be here?
It's not a good idea to cache the Shape object itself, but you can capture the HTML output from a Shape and cache that.
Every Orchard Shape has a corresponding object called the Metadata. This object contains, among other things, some event handlers that can run when the Shape is displaying or after it has been displayed. By using these event handlers, it is possible to cache the output of the Shape on the first call to a driver. Then for future calls to the driver, we can display the cached copy of the output instead of running through the expensive parts of the driver or template rendering.
Example:
using System.Web;
using DemoModule.Models;
using Orchard.Caching;
using Orchard.ContentManagement.Drivers;
using Orchard.DisplayManagement.Shapes;
namespace DemoModule.Drivers {
public class MyWidgetPartDriver : ContentPartDriver<MyWidgetPart> {
private readonly ICacheManager _cacheManager;
private readonly ISignals _signals;
public MyWidgetPartDriver(
ICacheManager cacheManager,
ISignals signals
) {
_cacheManager = cacheManager;
_signals = signals;
}
public class CachedOutput {
public IHtmlString Output { get; set; }
}
protected override DriverResult Display(MyWidgetPart part, string displayType, dynamic shapeHelper) {
return ContentShape("Parts_MyWidget", () => {
// The cache key. Build it using whatever is needed to differentiate the output.
var cacheKey = /* e.g. */ string.Format("MyWidget-{0}", part.Id);
// Standard Orchard cache manager. Notice we get this object by reference,
// so we can write to its field to save our cached HTML output.
var cachedOutput = _cacheManager.Get(cacheKey, ctx => {
// Use whatever signals are needed to invalidate the cache.
_signals.When(/* e.g. */ "ExpireCache");
return new CachedOutput();
});
dynamic shape;
if (cachedOutput.Output == null) {
// Output has not yet been cached, so we are going to build the shape normally
// and then cache the output.
/*
... Do normal (potentially expensive) things (call DBs, call services, etc.)
to prep shape ...
*/
// Create shape object.
shape = shapeHelper.Parts_MyWidget(/*...*/);
// Hook up an event handler such that after rendering the (potentially expensive)
// shape template, we capture the output to the cached output object.
((ShapeMetadata) shape.Metadata).OnDisplayed(displayed => cachedOutput.Output = displayed.ChildContent);
} else {
// Found cached output, so simply output it instead of building
// the shape normally.
// This is a dummy shape, the name doesn't matter.
shape = shapeHelper.CachedShape();
// Hook up an event handler to fill the output of this shape with the cached output.
((ShapeMetadata)shape.Metadata).OnDisplaying(displaying => displaying.ChildContent = cachedOutput.Output);
// Replacing the ChildContent of the displaying context will cause the display manager
// to simply use that HTML output and skip template rendering.
}
return shape;
});
}
}
}
EDIT:
Note that this only caches the HTML that is generated from your shape output. Things like Script.Require(), Capture(), and other side effects that you perform in your shape templates will not be played back. This actually bit me because I tried to cache a template that required its own stylesheet, but the stylesheets would only be brought in the first time.
Orchard supplies a service called the CacheManager, which is awesome and cool and makes caching super easy. It is mentioned in the docs, but it isn't a particularly helpful description of how to use it (http://docs.orchardproject.net/Documentation/Caching). Best place to see examples would be in the Orchard core code and third party modules such as Favicon and the twitter widgets (all of them one would hope).
Luckily other nice people have gone to the effort of searching orchards code for you and writing nice little blog posts about it. The developer of the LatestTwitter widget wrote a neat post: http://blog.maartenballiauw.be/post/2011/01/21/Writing-an-Orchard-widget-LatestTwitter.aspx . So did Richard of NogginBox: http://www.nogginbox.co.uk/blog/orchard-caching-by-time . And of course Bertrand has a helpful post on the subject as well: http://weblogs.asp.net/bleroy/archive/2011/02/16/caching-items-in-orchard.aspx
I have an IoC wrapper that uses MEF as it's DI container, an applicable snippet of the wrapper is shown below.
public static bool TryGetComponent<T>(out T component)
{
CompositionContainer container = RetrieveContainer();
T retrievedComponent = container.GetExportedValueOrDefault<T>();
if (retrievedComponent.Equals(default(T)))
{
component = default(T);
return false;
}
component = retrievedComponent;
return true;
}
Most of the exported components in the CompositionContainer specify a CreationPolicy of "Any".
[PartCreationPolicy(CreationPolicy.Any)]
For types that I create I can easily use the following import attribute to get MEF to serve the exported types as NonShared instances.
[Import(RequiredCreationPolicy = CreationPolicy.NonShared)]
However, since my IoC wrapper must also be used by classes that do not use MEF or any of its Import attributes and must use my IoC API to obtain instances exported types. I need a way to specify the CreationPolicy when I programmatically use the CompositionContainer to GetExports and GetExportedValues. Is this even possible without using import attributes?
If you really want to query the container exactly like as if you had a ImportAttribute with RequiredCreationPolicy=NonShared then try creating your own custom ContractBasedImportDefinition. One of the parameters for to the contructor is a CreationPolicy that represents the required creation policy.
Something like:
container.GetExports(new ContractBasedImportDefinition(
AttributedModelServices.GetContractName(type),
AttributedModelServices.GetTypeIdentity(type),
null,
ImportCardinality.ZeroOrMore,
false,
false,
CreationPolicy.NonShared));
Of course you can adjust the parameters as necessary but this will get you moving in the right direction and will cause the container to create NonShared versions of any part that is marked as Any (which is the default).
Well, CreationPolicy is passed as part of a component's metadata. This means, you should be able to query the metadata for the part, and see if it exists. The way CreationPolicy is specified in metadata is to use the full type name System.ComponentModel.Composition.CreationPolicy as the key, and the enum result as the value. So, knowing this we can build an extension method:
public static T GetExportedValueOrDefault<T>(this CompositionContainer container, CreationPolicy creationPolicy)
{
var metadataKey = typeof(CreationPolicy).FullName;
var lazy = container.GetExportedValueOrDefault<T, IDictionary<string, object>>();
if (lazy == null)
return default(T);
if (lazy.Metadata.ContainsKey(metadataKey))
{
// If the creation policy matches the required, return.
if (((CreationPolicy)lazy.Metadata[metadataKey]) == creationPolicy)
return lazy.Value;
}
else
{
// Return the value as we assume it satisfies the default CreationPolicy = Any
return lazy.Value;
}
return default(T);
}
Now, firstly we create our expected key, and then we grab a Lazy<T, TMetadata> instance which includes the type and any associated metadata as a Lazy<T, IDictionary<string, object>> instance. If the lazy comes back as null, we can fail early because there were no matching parts at all.
Next, we can check the metadata dictionary Lazy.Metadata to determine if the metadata exists. If it does, we need to cast and compare against our chosen metadata. If that succeeds, return our part instance.
If that doesn't succeed (e.g., if the part is using the implicit CreationPolicy of Any [i.e., the PartCreationPolicyAttribute is omitted from the export]), we'll assume that the part can be returned, as we can match on the default Any creation policy, so we can match both NonShared and Shared parts.
You should be able to use this in place of the normal GetExportedValueOrDefault<T> call:
T retrievedComponent = container.GetExportedValueOrDefault<T>(CreationPolicy.NonShared);
I am using a sping ws endpoint with jaxb marshalling/unmarshalling to proudce a list of Organisation objects (our local type). The endpoint is SOAP 1.1, no parameters supplied on the request message.
I understand JAXB doesn't handle lists very well, so I use a wrapper class.
#XmlRootElement(name="orgResponse", namespace=....)
public class OrganisationListWrapper {
private ArrayList<Organisation> organisationList;
public getOrganisationList() {
return organisationList;
}
public setOrganisationList(ArrayList<Organisation> organisationList) {
this.organisationList = organisationList;
}
}
The endpoint....
#PayloadRoot(localPart=.... namespace=....)
#ResponsePayload
public OrganisationListWrapper getOrganisations() {
OrganisationListWrapper wrapper = new OrganisationListWrapper();
wrapper.setOrganisationList(.... call service layer get list ....);
return wrapper;
}
This works fine and I get a SOAP payload with
<orgResponse>
<organisationList>
... contents of organisation 1
</organisationList>
<organisationList>
... comtents of organisation 2
</organisationList>
.... etc ....
</orgResponse>
The Organisation class is not JAXB annotated. It is part of a large list of pre-existing classes that are being exposed through web services for the first time. Trying to get by without going in and annotating them all by hand.
I was able to override the name OrganisationWrapper with orgResponse in the XmlRootElement annotation. I would like to override the organisationList name in the child element with organisation but haven't been able to find an annotation that does this.
I can replace the array list name with organisation and it will work fine, but our coding standard here required us to put List on the end of our list names. I would like to try and stick to that. I have tried XmlElement, but that produced a jaxb exception.
Any suggestions would be appreciated.
Because JAXB default the access type to PUBLIC_MEMBER, make sure you annotate the property (getter) and not the field:
#XmlElement(name="organisation")
public getOrganisationList() {
return organisationList;
}
If you want to annotate the field then add the following annotation to your class:
#XmlAccessorType(XmlAccessType.FIELD)