Does the size of a pool affect the number of invalid shares?


Many things can affect your stale/reject rate. An overclocked or faulty GPU could be making miscalculations. The pool's long polling might not be working properly. Even network instability could cause rejects due to duplicate shares (the share was received by the server, but your miner got an error so it tries again).

The way pool size would affect rejects is that a large number of miners slow down long polling on the server side. Everything else being equal it takes longer for the server to notify 10 000 workers of a block change than it would 500 workers.

So in general you can expect lower stale rate on a small pool, unless the small pool effect is negated by really slow server hardware or some other...

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If you prefer to exercise more direct control over the sizes of individual memory components, you can disable automatic memory management and configure the database for manual memory management. There are two different manual memory management methods for the SGA, and two for the instance PGA.

The two manual memory management methods for the SGA vary in the amount of effort and knowledge required by the DBA. With automatic shared memory management, you set target and maximum sizes for the SGA. The database then sets the total size of the SGA to your designated target, and dynamically tunes the sizes of many SGA components. With manual shared memory management, you set the sizes of several individual SGA components, thereby determining the overall SGA size. You then manually tune these individual SGA components on an ongoing basis.

For the instance PGA, there is automatic PGA memory management, in which you set a target size for the instance PGA. The database then sets...

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A connection pool is a standard technique used to maintain long running connections in memory for efficient re-use, as well as to provide management for the total number of connections an application might use simultaneously.

Particularly for server-side web applications, a connection pool is the standard way to maintain a “pool” of active database connections in memory which are reused across requests.

SQLAlchemy includes several connection pool implementations which integrate with the Engine. They can also be used directly for applications that want to add pooling to an otherwise plain DBAPI approach.

Connection Pool Configuration

The Engine returned by the create_engine() function in most cases has a QueuePool integrated, pre-configured with reasonable pooling defaults. If you’re reading this section only to learn how to enable pooling - congratulations! You’re already done.

The most common QueuePool tuning parameters can be passed directly to...

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First of all: try to delete and recreate DAG-files.

Also remove any additional options from cmd-line and overclocking.

If you get any invalid shares it means you may have few ethminer windows or even rigs with the same hashrate, if yes dont use the same value in mining address.

For example you have two miners with 60MHash, you need to put 61@ADDRESS and 60@ADDRESS.

Hashrate is mainfactor to generate shares with unique difficulity, it's also internal indentifier regarding miners on your address.

If you misconfigured it, some shares may get rejected. But if you still getting invalid shares even if you have valid settings, and you are not trying to lower target in ethminer to cheat us.

Then just contact...

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I am writing a utility that must make thousands of network requests. Each request receives only a single, small packet in response (similar to ping), but may take upwards of several seconds to complete. Processing each response completes in one (simple) line of code.

The net effect of this is that the computer is not IO-bound, file-system-bound, or CPU-bound, it is only bound by the latency of the responses.

This is similar to, but not the same as There is a way to determine the ideal number of threads? and Java best way to determine the optimal number of threads [duplicate]... the primary difference is that I am only bound by latency.

I am using an ExecutorService object to run the threads and a Queue> to track threads that need to have results retrieved:

ExecutorService executorService = Executors.newFixedThreadPool(threadPoolSize); Queue> futures = new LinkedList>(); for (int quad3 = 0 ; quad3 < 256 ; ++quad3) { for (int quad4 = 0 ; quad4 < 256 ;...
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Question: I am trying to expand by shared_pool size and I get the ORA-04033 error:

SQL> alter system set shared_pool_size=10g

ORA-02097: parameter cannot be modified because specified value is invalid
ORA-04033: Insufficient memory to grow pool

How do I fix the ORA-04033 error?

Answer: As the ORA-04033 message suggests, you do not have enough RAM allocated to the SGA to allow you to create a 10 gig shared pool.

The oerr utility shows this for the ORA-04033 error, which is not very helpful:

ORA-04033: Insufficient memory to grow pool

Cause: The system had insufficient memory to grow the pool to the specified size.

Action: Specify a smaller value to grow the pool.

The ORA-04030 fix depends on your release of Oracle and you use of the sga_max_size parameter and whether you have deployed Automatic Shared Memory Management (ASMM), a mechanism to automatically morph the pool...

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