When trying to run the following in Redis using booksleeve.
using (var conn = new RedisConnection(server, port, -1, password))
{
var result = conn.Server.FlushDb(0);
result.Wait();
}
I get an error saying:
This command is not available unless the connection is created with
admin-commands enabled"
I am not sure how do i execute commands as admin? Do I need to create an a/c in db with admin access and login with that?
Updated answer for StackExchange.Redis:
var conn = ConnectionMultiplexer.Connect("localhost,allowAdmin=true");
Note also that the object created here should be created once per application and shared as a global singleton, per Marc:
Because the ConnectionMultiplexer does a lot, it is designed to be
shared and reused between callers. You should not create a
ConnectionMultiplexer per operation. It is fully thread-safe and ready
for this usage.
Basically, the dangerous commands that you don't need in routine operations, but which can cause lots of problems if used inappropriately (i.e. the equivalent of drop database in tsql, since your example is FlushDb) are protected by a "yes, I meant to do that..." flag:
using (var conn = new RedisConnection(server, port, -1, password,
allowAdmin: true)) <==== here
I will improve the error message to make this very clear and explicit.
You can also set this in C# when you're creating your multiplexer - set AllowAdmin = true
private ConnectionMultiplexer GetConnectionMultiplexer()
{
var options = ConfigurationOptions.Parse("localhost:6379");
options.ConnectRetry = 5;
options.AllowAdmin = true;
return ConnectionMultiplexer.Connect(options);
}
For those who like me faced the error:
StackExchange.Redis.RedisCommandException: This operation is not
available unless admin mode is enabled: ROLE
after upgrading StackExchange.Redis to version 2.2.4 with Sentinel connection: it's a known bug, the workaround was either to downgrade the client back or to add allowAdmin=true to the connection string and wait for the fix.
Starting from 2.2.50 public release the issue is fixed.
Related
I am trying to create an aws instance using jclouds 1.9.0 and then run a script on it (via ssh). I am following the example locate here but I am getting authentication failed errors when the client (java program) tries to connect at the instance. The AWS console show that instance is up and running.
The example tries to create a LoginCrendentials object
String user = System.getProperty("user.name");
String privateKey = Files.toString(new File(System.getProperty("user.home") + "/.ssh/id_rsa"), UTF_8);
return LoginCredentials.builder().user(user).privateKey(privateKey).build();
which is latter used from the ssh client
responses = compute.runScriptOnNodesMatching(
inGroup(groupName), // predicate used to select nodes
exec(command), // what you actually intend to run
overrideLoginCredentials(login) // use my local user & ssh key
.runAsRoot(false) // don't attempt to run as root (sudo)
.wrapInInitScript(false));
Some Login information are injected to the instance with following commands
Statement bootInstructions = AdminAccess.standard();
templateBuilder.options(runScript(bootInstructions));
Since I am on Windows machine the creation of LoginCrendentials 'fails' and thus I alter its code to
String user = "ec2-user";
String privateKey = "-----BEGIN RSA PRIVATE KEY-----.....-----END RSA PRIVATE KEY-----";
return LoginCredentials.builder().user(user).privateKey(privateKey).build();
I also to define the credentials while building the template as described in "EC2: In Depth" guide but with no luck.
An alternative is to build instance and inject the keypair as follows, but this implies that I need to have the ssh key stored in my AWS console, which is not currently the case and also breaks the functionality of running a script (via ssh) since I can not infer the NodeMetadata from a RunningInstance object.
RunInstancesOptions options = RunInstancesOptions.Builder.asType("t2.micro").withKeyName(keypair).withSecurityGroup(securityGroup).withUserData(script.getBytes());
Any suggestions??
Note: While I am currently testing this on aws, I want to keep the code as decoupled from the provider as possible.
Update 26/10/2015
Based on #Ignasi Barrera answer, I changed my implementation by adding .init(new MyAdminAccessConfiguration()) while creating the bootInstructions
Statement bootInstructions = AdminAccess.standard().init(new MyAdminAccessConfiguration());
templateBuilder.options(runScript(bootInstructions));
Where MyAdminAccessConfiguration is my own implementation of the AdminAccessConfiguration interface as #Ignasi Barrera described it.
I think the issue relies on the fact that the jclouds code runs on a Windows machine and jclouds makes some Unix assumptions by default.
There are two different things here: first, the AdminAccess.standard() is used to configure a user in the deployed node once it boots, and later the LoginCredentials object passed to the run script method is used to authenticate against the user that has been created with the previous statement.
The issue here is that the AdminAccess.standard() reads the "current user" information and assumes a Unix System. That user information is provided by this Default class, and in your case I'm pretty sure it will fallback to the catch block and return an auto-generated SSH key pair. That means, the AdminAccess.standard() is creating a user in the node with an auto-generated (random) SSH key, but the LoginCredentials you are building don't match those keys, thus the authentication failure.
Since the AdminAccess entity is immutable, the better and cleaner approach to fix this is to create your own implementation of the AdminAccessConfiguration interface. You can just copy the entire Default class and change the Unix specific bits to accommodate the SSH setup in your Windows machine. Once you have the implementation class, you can inject it by creating a Guice module and passing it to the list of modules provided when creating the jclouds context. Something like:
// Create the custom module to inject your implementation
Module windowsAdminAccess = new AbstractModule() {
#Override protected void configure() {
bind(AdminAccessConfiguration.class).to(YourCustomWindowsImpl.class).in(Scopes.SINGLETON);
}
};
// Provide the module in the module list when creating the context
ComputeServiceContext context = ContextBuilder.newBuilder("aws-ec2")
.credentials("api-key", "api-secret")
.modules(ImmutableSet.<Module> of(windowsAdminAccess, new SshjSshClientModule()))
.buildView(ComputeServiceContext.class);
I am in the process of upgrading asp.net membership to the new simplemembership provider in MVC4. This is an Azure/Sql Azure app which runs fine on localhost but fails when deployed. I have code in a transaction as follows:
TransactionOptions toptions = new TransactionOptions();
toptions.IsolationLevel = System.Transactions.IsolationLevel.Serializable;
using (TransactionScope trans = new TransactionScope(TransactionScopeOption.Required, toptions))
{
try
{
... do a bunch of database stuff in a single dbContext ...
var roleprov = (SimpleRoleProvider)Roles.Provider;
string[] roles = roleprov.GetRolesForUser(Username);
// above line fails with The transaction manager has disabled its support for remote/network transactions. (Exception from HRESULT: 0x8004D024)
}
}
I am using this technique to populate the Roles classes. The stack trace seems to indicate that it is indeed trying to fire off a sub-transaction to complete that call. The simplemembership tables are in a different db. How can I retrieve role info from the role provider inside the context of a separate transaction?
The problem is that GetRolesForUser causes a new connection to open to a second database, and that in turn picks up that it is in a TransactionScope. In turn this (MSDN - System.Transactions Integration with SQL Server) then promotes to the DTC. You could try a few options:
Get roles before the transaction starts
You could retrieve string[] roles outside your TransactionScope. Is there a reason you need to get them inside the scope? Given that you say:
How can I retrieve role info from the role provider inside the context of a separate transaction
it sounds like you could get the role info before the TransactionScope and have no problems.
Turn off transactions on the simple membership connection string
You can tell a connection string not to take part in transactions by putting "enlist=false" (see SqlConnection.ConnectionString) in the connection string, so this might be one option for you if you never need transactions on the database you use for Simple Membership.
Try opening the Simple Membership connection before the transaction
For SimpleRoleProvider it creates it's database object, and then opens it the first time it uses it. But, it doesn't close it until .... Scratch that, the connection is opened on each call to GetRolesForUser so you are out of luck. I was thinking you could call GetRolesForUser once before TransactionScope is opened, and then again inside the scope using the already open connection - you can't.
Play with the IObjectContextAdapter
Disclaimer: I can't promise this will work as I can't test with your setup.
You can play tricks to prevent promotion with two connection strings by opening the non-transaction connection string outside the transaction scope first, and then the transaction shouldn't be promoted. This can also be used if you cause the same connection to Close and then Open inside the same transaction scope (which would otherwise cause promotion).
You could try this with your context, and see if that stopped the GetRolesForUser promoting the transaction, but I doubt that would work as GetRolesForUser causes the connection to open if it isn't already. As I can't test in your scenario, I will include it in case it helps.
using (var db = new ExampleContext())
{
var adapter = db as System.Data.Entity.Infrastructure.IObjectContextAdapter;
using (var conn = adapter.ObjectContext.Connection)
{
conn.Open();
using (TransactionScope scope = new TransactionScope(TransactionScopeOption.Required))
{
// perform operations
db.SaveChanges();
// perform more operations
db.SaveChanges();
// perform even more operations
db.SaveChanges();
// If you don't complete, the transaction won't commit and you will lose the changes
scope.Complete();
}
}
}
I'm using SQL Azure in a Windows Azure app running as a cloud service. Most of the time my database actions works completely fine (that is, after handling all sorts of timeouts and what not), however i'm running into a problem that seems
using (var connection = new SqlConnection(m_connectionString))
{
m_ConnectionRetryPolicy.ExecuteAction(() => connection.Open());
using (var command = connection.CreateCommand())
{
command.CommandText = "SELECT * FROM X WHERE Y = Z";
var reader = m_CommandRetryPolicy.ExecuteAction(() => command.ExecuteReader());
return LoadData(reader).FirstOrDefault();
}
}
The line that fails is the Command.ExecuteReader with an:
ExecuteReader requires an open and available Connection. The connection's current state is closed
Things that i have already considered
I'm not "reusing" an old connection or saving a connection is a member variable
There should be no concurrency issues - the repository class that these methods belong to is created each time it is needed
Have anyone else experienced this? I could of course just add this to the list of exception which would yield a retry, but I'm not very comfortable with that as
I had a bunch of these errors a few days ago (West Europe) on my production deployment, but they went away by themselves. At the same time I was seeing timeouts, throttling and other errors from SQL Azure. I assume that there was a temporary problem with the platform (or at least the server that I am running on).
You probably aren't doing anything wrong in your code, but are suffering from degraded performance on SQL Azure. Try and handle the errors, perform retries, exponential back-off, queues (to reduce concurrency), splitting your load across databases — that sort of thing.
write every thing within try and catch,finally block.
as follows:
try
{
con.open();
m_ConnectionRetryPolicy.ExecuteAction(() => connection.Open());
using (var command = connection.CreateCommand())
{
command.CommandText = "SELECT * FROM X WHERE Y = Z";
var reader = m_CommandRetryPolicy.ExecuteAction(() => command.ExecuteReader());
return LoadData(reader).FirstOrDefault();
}
con.close();
}
catch(exception ex)
{
}
finally
{
con.close();
}
Remember to close connection in finally block as well.
There is an Enterprise Library that MS has produced specifically for SQL Azure, here are some examples from their patterns and Practice.
It's similar to what you are doing, however it does more on the reliability (and these examples show how to get a reliable connection)
http://msdn.microsoft.com/en-us/library/hh680899(v=pandp.50).aspx
Are you sure it's the reader that's failing and not the opening of the connection? I'm encountering an exception when I wrap the connection.Open() in the m_ConnectionRetryPolicy.ExecuteAction().
However it works just fine for me if I skip the ExecuteAction wrapper and open the connection using connection.OpenWithRetry(m_ConnectionRetryPolicy).
And I'm also using command.ExecuteReaderWithRetry(m_ConnectionRetryPolicy) which is working for me.
I have no idea though why it's not working when wrapped in ExecuteAction though.
I believe this means that Azure has closed the connection behind the scenes, without telling the connection pooler. This is by design. So, the connection pooler gives you what it thinks is an available, open connection, but when you try to use it, it finds out it's not open after all.
This seems very clunky to me, but it's the way Azure is at the moment.
I have a service with application scope, not transactional.
I have a service method which:
uses the injected dataSource to create a stored procedure call [using Sql.call{...}]. Executes and traverse the resultset.
Based on the resultset, I subdivide the resultsets into equal sizes chunks and process them in multiple threads.
Each thread tries to do Sql sql = new Sql(dataSource)
Here a deadlock occurs.
Why is that? Does dataSource not return a possibly new or an idle connection?
Try to look into Gpars : It's a groovy parallalization framework.
I run into exactly the same issue. After hours of searching i've found the solution.
In your Datasource.groovy configfile you are able to set the parameters for the connection pooling to the database.
I've changed the minIdle, maxIdle and maxActive settings of the http://commons.apache.org/proper/commons-dbcp/apidocs/org/apache/commons/dbcp/BasicDataSource.html so that my configfile looks something like this:
dataSource {
url = "jdbc:mysql://127.0.0.1/sipsy_dev?autoReconnect=true&zeroDateTimeBehavior=convertToNull"
driverClassName = "com.mysql.jdbc.Driver"
username = "sipsy_dev"
password = "sipsy_dev"
pooled = true
properties {
minEvictableIdleTimeMillis=1800000
timeBetweenEvictionRunsMillis=1800000
numTestsPerEvictionRun=3
testOnBorrow=true
testWhileIdle=true
testOnReturn=true
minIdle=100
maxIdle=250
maxActive=500
validationQuery="SELECT 1"
}
dialect = 'org.hibernate.dialect.MySQL5InnoDBDialect'
}
When you are not in a transaction, you have to release the connection that GroovySQL picks up from the datasource. The pool runs out of connections and that's why it locks up.
Inside a transaction TransactionAwareDataSourceProxy will take care of sharing the connection and therefore releasing the connection from GroovySQL isn't required in that case. See http://jira.grails.org/browse/GRAILS-5454 for details.
This is a better way to use GroovySQL in Grails since the OpenSessionInView (OSIV) interceptor will take care of closing the connection and it will share the same database connection as Hibernate. This method works in both cases: inside transactions and outside transactions.
Sql sql = new Sql(sessionFactory.currentSession.connection())
In SQL Server 2005, is there a way to specify more than one connection string from within a .NET Application, with one being a primary preferred connection, but if not available it defaults to trying the other connection (which may be going to a diff DB / server etc)?
If nothing along those exact lines, is there anything we can use, without resorting to writing some kind of round-robin code to check connections?
Thanks.
We would typically use composition on our SqlConnection objects to check for this. All data access is done via backend classes, and we specify multiple servers within the web/app.config. (Forgive any errors, I am actually writing this out by hand)
It would look something like this:
class MyComponent
{
private SqlConnection connection;
....
public void CheckServers()
{
// Cycle through servers in configuration files, finding one that is usable
// When one is found assign the connection string to the SqlConnection
// a simple but resource intensive way of checking for connectivity, is by attempting to run
// a small query and checking the return value
}
public void Open()
{
connection.Open();
}
public ConnectionState State
{
get {return connection.State;}
set {connection.State = value;}
}
// Use this method to return the selected connection string
public string SelectedConnectionString
{
get { return connection.ConnectionString; }
}
//and so on
}
This example includes no error checking or error logging, make sure you add that, so the object can optionally report which connections failed and why.
Assuming that you'd want to access the same set of data, then you'd use clustering or mirroring to provide high availability.
SQLNCLI provider supports SQL Server database mirroring
Provider=SQLNCLI;Data Source=myServer;Failover Partner=myMirrorServer
Clustering just uses the virtual SQL instance name.
Otherwise, I can't quite grasp why you'd want to do this...
Unfortunately there are no FCL methods that do this - you will need to implement this yourself.