I installed Service Control(V1.20.0) recently to my QA server, I install it using ServiceControl Management Utility , I didn’t change the default values, I didn’t move DB location.
I was able to browse to the RavenDB when I am in maintenance mode.
The particular endpoints are created, I also have non-expired license.
This is what i found in the db log file
Microsoft.Isam.Esent.Interop.EsentInvalidInstanceException: Invalid
instance handle at Microsoft.Isam.Esent.Interop.Api.Check(Int32
err) in
C:\Work\ravendb\SharedLibs\Sources\managedesent-61618\EsentInterop\Api.cs:line
2739 at
Microsoft.Isam.Esent.Interop.Api.JetBeginSession(JET_INSTANCE
instance, JET_SESID& sesid, String username, String password) in
C:\Work\ravendb\SharedLibs\Sources\managedesent-61618\EsentInterop\Api.cs:line
823 at
Raven.Storage.Esent.StorageActions.DocumentStorageActions..ctor(JET_INSTANCE
instance, String database, TableColumnsCache tableColumnsCache,
OrderedPartCollection`1 documentCodecs, IUuidGenerator uuidGenerator,
IDocumentCacher cacher, EsentTransactionContext transactionContext,
TransactionalStorage transactionalStorage) in
c:\Builds\RavenDB-Stable-2.5\Raven.Database\Storage\Esent\StorageActions\General.cs:line
76
With the amazing help of Particular team, I was able to solve the issue. In my case the problem was I have created the Particular.ServiceControl queue manually. And it needs to be transnational, this was the error i was getting in event viewer:
Queue must be transactional if you configure your endpoint to be
transactional
Deleting the queue, and let Service Control Management tool take care of creating all necessary queues.
Related
Problem
A session value is not being retrieved in a Razor view and is causing faulty logic.
Environment
Redis sentinel with sentinel on web servers but only a single redis master and single redis slave. The redis connection string is pointing to both master and slave.
Code
In a controller before the view:
var fooLocal = fooMapper.Map(fooDbCall.GetFromDb(fooValue));
if (fooLocal != null)
{
Session["FooSession"] = fooLocal.fooProperty;
}
else
{
Session["FooSession"] = false;
}
In the view
#if (fooRazorVal == 123)
{
// show some stuff
}
else if (!((bool?)Session["FooSession"] ?? false) && (fooRazorVal2 == 456))
{
// show error message
}
else
{
// show other stuff
}
Result
The error message is shown even when an account in question has been walked back through the code and database to verify it should not be false let alone null. Other session values are stored and retrieved fine or else you wouldn't even make it this far in my process.
Investigation
As I mentioned, all other code bits and the database have been verified. I added a logging class and there are lots of entries like so:
[Info]GetItemFromSessionStore => Session Id: ctps3urcqwm0tpezo5bbmqzj, Session provider object: 4686063 => Can not lock, Someone else has lock and lockId is 636901606595110722
[Info]GetItemFromSessionStore => Session Id: ctps3urcqwm0tpezo5bbmqzj, Session provider object: 26422156 => Lock taken with lockId: 636901606595110722
[Info]GetItemFromSessionStore => Session Id: ctps3urcqwm0tpezo5bbmqzj, Session provider object: 4686063 => Can not lock, Someone else has lock and lockId is 636901606595110722
However, given the sheer number of them, I'm wondering if this is actually an error or the RedisSessionStateProvider working as intended. I did see that it uses SETNX to acquire locks. Unfortunately, I'm not well versed enough in redis semantics to know if this is causing an issue.
I did see a note on the Redis docs about this being an old approach and to use RedLock instead. However, as I understand RedLock, a single master/single slave setup is not sufficient although it does support retries so maybe it would work anyway. I'm also curious if I should roll a simple custom provider that lets StackExhange's ConnectionMultiplexer work without extra locks or custom scripts and if I do need locks to use one of the C# libraries for RedLock.
By design, Redis keys are locked during update, you don't need to lock them. Indeed, Redis uses a single thread to process commands, so each operation is atomic. Other clients are blocked during the processing of a given command, that's why you mustn't perform queries with a long execution time and you are getting this error.
To prevent that one must implement distributed lock. Distributed locks are a very useful primitive in many environments where different processes must operate with shared resources in a mutually exclusive way.
Here are the different implementation for different language.
Implementations
Here are a few links to implementations already available that can be used for reference.
• Redlock-rb (Ruby implementation). There is also a fork of Redlock-rb that adds a gem for easy distribution and perhaps more.
• Redlock-py (Python implementation).
• Aioredlock (Asyncio Python implementation).
• Redlock-php (PHP implementation).
• PHPRedisMutex (further PHP implementation)
• Redsync.go (Go implementation).
• Redisson (Java implementation).
• Redis::DistLock (Perl implementation).
• Redlock-cpp (C++ implementation).
• Redlock-cs (C#/.NET implementation).
• RedLock.net (C#/.NET implementation). Includes async and lock extension support.
• ScarletLock (C# .NET implementation with configurable datastore)
• node-redlock (NodeJS implementation). Includes support for lock extension.
See if this helps.
Can we use graph database neo4j with react js? If not so is there any alternate option for including graph database in react JS?
Easily, all you need is neo4j-driver: https://www.npmjs.com/package/neo4j-driver
Here is the most simplistic usage:
neo4j.js
//import { v1 as neo4j } from 'neo4j-driver'
const neo4j = require('neo4j-driver').v1
const driver = neo4j.driver('bolt://localhost', neo4j.auth.basic('username', 'password'))
const session = driver.session()
session
.run(`
MATCH (n:Node)
RETURN n AS someName
`)
.then((results) => {
results.records.forEach((record) => console.log(record.get('someName')))
session.close()
driver.close()
})
It is best practice to close the session always after you get the data. It is inexpensive and lightweight.
It is best practice to only close the driver session once your program is done (like Mongo DB). You will see extreme errors if you close the driver at a bad time, which is incredibly important to note if you are beginner. You will see errors like 'connection to server closed', etc. In async code, for example, if you run a query and close the driver before the results are parsed, you will have a bad time.
You can see in my example that I close the driver after, but only to illustrate proper cleanup. If you run this code in a standalone JS file to test, you will see node.js hangs after the query and you need to press CTRL + C to exit. Adding driver.close() fixes that. Normally, the driver is not closed until the program exits/crashes, which is never in a Backend API, and not until the user logs out in the Frontend.
Knowing this now, you are off to a great start.
Remember, session.close() immediately every time, and be careful with the driver.close().
You could put this code in a React component or action creator easily and render the data.
You will find it no different than hooking up and working with Axios.
You can run statements in a transaction also, which is beneficial for writelocking affected nodes. You should research that thoroughly first, but transaction flow is like this:
const session = driver.session()
const tx = session.beginTransaction()
tx
.run(query)
.then(// same as normal)
.catch(// errors)
// the difference is you can chain multiple transactions:
const tx1 = await tx.run().then()
// use results
const tx2 = await tx.run().then()
// then, once you are ready to commit the changes:
if (results.good !== true) {
tx.rollback()
session.close()
throw error
}
await tx.commit()
session.close()
const finalResults = { tx1, tx2 }
return finalResults
// in my experience, you have to await tx.commit
// in async/await syntax conditions, otherwise it may not commit properly
// that operation is not instant
tl;dr;
Yes, you can!
You are mixing two different technologies together. Neo4j is graph database and React.js is framework for front-end.
You can connect to Neo4j from JavaScript - http://neo4j.com/developer/javascript/
Interesting topic. I am using the driver in a React App and recently experienced some issues. I am closing the session every time a lifecycle hook completes like in your example. When there where more intensive queries I would see a timeout error. Going back to my setup decided to experiment by closing the driver in some more expensive queries and it looks like (still need more testing) the crashes are gone.
If you are deploying a real-world application I would urge you to think about Authentication and Authorization when using a DB-React setup only as you would have to store username/password of the neo4j server in the client. I am looking into options of having the Neo4J server issuing a token and receiving it for Authorization but the best practice is for sure to have a Node.js server in the middle with something like Passport to handle Authentication.
So, all in all, maybe the best scenario is to only use the driver in Node and have the browser always communicating with the Node server using axios...
I have a problem with changing the standard options used by an Axis 1.4 generated web service client code.
We consume a certain web service of a partner who is using the old RPC/Encoded style, which basically means we're not able to go for Axis 2 but are limited to Axis 1.4.
The service client is retrieving data from the remote server through our proxy which actually runs quite nicely.
Our application is deployed as a servlet. The retrieved response of the foreign web service is inserted into a (XML) document we provide to our internal systems/CMS.
But if the external service is not responding - which didn't happen yet but might happen at anytime - we want to degrade nicely and return our produced XML document without the calculated web service information within a resonable time.
The data retrieved is optional (if this specific calculation is missing it isn't a big issue at all).
So I tried to change the timeout settings. I did apply/use all methods and keys I could find in the documentation of axis to alter the connection and socket timeouts by searching the web.
None of these seems to influence the connection timeouts.
Can anyone give me advice how to alter the settings for an axis stub/service/port based on version 1.4?
Here's an example for the several configurations I tried:
MyService service = new MyServiceLocator();
MyServicePort port = null;
try {
port = service.getMyServicePort();
javax.xml.rpc.Stub stub = (javax.xml.rpc.Stub) port;
stub._setProperty("axis.connection.timeout", 10);
stub._setProperty(org.apache.axis.client.Call.CONNECTION_TIMEOUT_PROPERTY, 10);
stub._setProperty(org.apache.axis.components.net.DefaultCommonsHTTPClientProperties.CONNECTION_DEFAULT_CONNECTION_TIMEOUT_KEY, 10);
stub._setProperty(org.apache.axis.components.net.DefaultCommonsHTTPClientProperties.CONNECTION_DEFAULT_SO_TIMEOUT_KEY, 10);
AxisProperties.setProperty("axis.connection.timeout", "10");
AxisProperties.setProperty(org.apache.axis.client.Call.CONNECTION_TIMEOUT_PROPERTY, "10");
AxisProperties.setProperty(org.apache.axis.components.net.DefaultCommonsHTTPClientProperties.CONNECTION_DEFAULT_CONNECTION_TIMEOUT_KEY, "10");
AxisProperties.setProperty(org.apache.axis.components.net.DefaultCommonsHTTPClientProperties.CONNECTION_DEFAULT_SO_TIMEOUT_KEY, "10");
logger.error(AxisProperties.getProperties());
service = new MyClimateServiceLocator();
port = service.getMyServicePort();
}
I assigned the property changes before the generation of the service and after, I set the properties during initialisation, I tried several other timeout keys I found, ...
I think I'm getting mad about that and start to forget what I tried already!
What am I doing wrong? I mean there must be an option, mustn't it?
If I don't find a proper solution I thought about setting up a synchronized thread with a timeout within our code which actually feels quite awkward and somehow silly.
Can you imagine anything else?
Thanks in advance
Jens
axis1.4 java client soap wsdl2java rpc/encoded xml servlet generated alter change setup stub timeout connection socket keys methods
I think it may be a bug, as indicated here:
https://issues.apache.org/jira/browse/AXIS-2493?jql=text%20~%20%22CONNECTION_DEFAULT_CONNECTION_TIMEOUT_KEY%22
Typecast service port object to org.apache.axis.client.Stub.
(i.e)
org.apache.axis.client.Stub stub = (org.apache.axis.client.Stub) port;
Then set all the properties:
stub._setProperty(org.apache.axis.client.Call.CONNECTION_TIMEOUT_PROPERTY, 10);
stub._setProperty(org.apache.axis.components.net.DefaultCommonsHTTPClientProperties.CONNECTION_DEFAULT_CONNECTION_TIMEOUT_KEY, 10);
stub._setProperty(org.apache.axis.components.net.DefaultCommonsHTTPClientProperties.CONNECTION_DEFAULT_SO_TIMEOUT_KEY, 10);
I have a Windows Service that I inherited from a departed developer. The Windows Service is running just fine in the QA environment. When I install the service and run it locally, I receive this error:
Service cannot be started. System.InvalidOperationException: The requested Performance Counter is not a custom counter, it has to be initialized as ReadOnly.
Here is the code:
ExternalDataExchangeService exchangeService = new ExternalDataExchangeService();
workflowRuntime.AddService(exchangeService);
workflowRuntime.AddService(new SqlTrackingService(AppContext.SqlConnectionImportLog));
ChallengerWorkflowService challengerWorkflowService = new ChallengerWorkflowService();
challengerWorkflowService.SendDataEvent += new EventHandler<SendDataEventArgs>(challengerWorkflowService_SendDataEvent);
workflowRuntime.AddService(challengerWorkflowService);
workflowRuntime.StartRuntime(); <---- Exception is thrown here.
Check for installer code. Often you will find counters are created within an installation (which is going to of been run under admin privledges on client site) and the code then uses them as though they exist - but will not try create them because they do not expect to have the permissions.
If you just get the source and then try run it, the counters / counter classes do not exist so you fall over immediately. (Alternatively check whether the counter exists / you have local admin if they wrote the code to create it in the service.)
Seen it before so mentioned it.
Attach Debugger and break on InvalidOperationException (first-chance, i.e. when thrown)?
I'm using CreateService to install a windows service on Windows XPE. I'd like to set things up so that only the Administrator can start/stop/pause/resume the service.
Right now I'm using the following to install the service:
schService = CreateService(schSCManager,
ServiceName,
ServiceDisplayName, // service name to display
SERVICE_ALL_ACCESS, // desired access
SERVICE_WIN32_OWN_PROCESS, // service type
SERVICE_AUTO_START, // start type
SERVICE_ERROR_NORMAL, // error control type
binaryPathName, // service's binary (this program)
NULL, // no load ordering group
NULL, // no tag identifier
NULL, // no dependencies
NULL, // LocalSystem account
NULL); // no password
And the service ends up with security such that members of the PowerUsers group can start and stop the service. I've figured out that I can use sc sdshow to examine the security descriptor, and I've worked out an SDDL line that would do the right thing for us.
I've also learned that our Win XPE install doesn't have the sc.exe binary on it, so we can't really use that to setup this particular system.
So, what I need to know is: What are the APIs I need to use, to set the security descriptor on this service around the time I do the CreateService call. I'm completely unfamiliar with the Windows security APIs, so I just don't know where to start.
UPDATE: The answer is SetServiceObjectSecurity (below). Next question: What's the best way to setup the SecurityDescriptor? Is it best to get the default descriptor, then modify it? Or should I just create a completely new descriptor?
I'm not really familiar with Windows XP Embedded, but normally you would achieve what you are after using the SetServiceObjectSecurity function. Use the handle you get from CreateService and build a security descriptor that matches what you want.