multicore

In Single Solr Instance, multiple core(s) are there. No Shards, Replication and Cloud concept involved. Now how to search over multiple core in this scenario? To search across cores, you'll have to use sharding. If the schema for both cores are identical, you can just query one core and provide the shards parameter. If the schema is different, create a separate core that have a merged schema of both the target schemas, then query that core with the two separate cores as shards. Having FieldA, FieldB in core0 and FieldB, FieldC in core1 would require a schema with FieldA, FieldB, FieldC defined

How do you configure SqLite 3 to process a single query using more than 1 core of a CPU ? Since version 3.8.7, SQLite can use multiple threads for parallel sorting of large data sets. sqlite3 itself does not do that. However, I have a project called multicoresql on github that has utility programs and a C library for spreading sql queries onto multiple cores. It uses sharding so you have to break your large database or datafile into multiple sqlite3 database files. A single SQL query must be written as two SQL queries, a map query that first runs on all the shards, and a reduce query to

I am trying to use the doSMP package that provides a parallel backend for the foreach package. Can you point out what I do wrong? Indeed, using foreach in that way increases significantly the computing time... #------register doSMP to be used with foreach------ library(doSMP) w <- startWorkers(4) registerDoSMP(w) #-------------------------------------------------- #------A simple function------ sim <- function(a, b) { return(10 * a + b) } avec <- 1:200 bvec <- 1:400 #----------------------------- #------The naive method------ ptime <- system.time({ mat <- matrix(NA, nrow=length(avec), ncol

The details of the MESI protocol for multicore processors would be really important for me, but I can't find them anywhere. Even http://www.intel.com/content/dam/doc/manual/64-ia-32-architectures-software-developer-vol-3a-part-1-manual.pdf doesn't contain enough detail. For instance: assume a private L1 and shared L2 cache. If the state of a line is exclusive in L1, then is it exclusive in L2 too (or invalid, because only in one cache could be the state of a line exclusive)? And clearly, if another core writes this line, the state of the previously exclusive line in L1 becomes invalid, but how

How do I configure HAYSTACK_SOLR_URL when using multiple cores? I've set it to the address of core0, and that works, but only using one core… The docs aren't that obvious to me… it just says ... # ...or for multicore... HAYSTACK_SOLR_URL = 'http://127.0.0.1:8983/solr/mysite' What is mysite? I'm actually running apache-solar-3.3.0/example with the multicore directory copied over the example directory, and the schema and conf files/directories updated. Many thanks. <cores adminPath="/admin/cores"> <core name="core0" instanceDir="core0" /> <core name="core1" instanceDir="core1" /> </cores> So,

I want to understand performance in multithreaded environments. For that I have written a small test that I ran on my machine (quad-core Intel, Windows XP, Sun JDK 1.6.0_20), with surprising results. The test is basically a thread-safe counter that is synchronized using either the synchronized keyword or an explicit lock. Here is the code: import java.util.concurrent.locks.ReentrantLock; public class SynchronizedPerformance { static class Counter { private static final int MAX = 1 << 24; int count; long lastLog = 0; private final ReentrantLock lock = new ReentrantLock(); private int

In a single thread program, how are changes made by thread in core 1 made visible to another core 2, so that after a context switch the thread (now running on core 2) will have updated value? Consider the following example: The value in main memory for variable x is 10. The thread runs on core 1 and changes x to 5, which is still in cache and not yet flushed to main memory as we are not using any memory barrier. A context switch occurs and the thread moves from core 1 to core 2. The thread reads the value of x . What would be the value of x if thread resumes execution in core 2 after the

I think the topic says it all. What's the difference, if any, between parallel and multicore programming? Thanks. Mutli-core is a kind of parallel programming. In particular, it is a kind of MIMD setup where the processing units aren't distributed, but rather share a common memory area, and can even share data like a MISD setup if need be. I believe it is even disctinct from multi-processing, in that a multi-core setup can share some level of caches, and thus cooperate more efficiently than CPUs on different cores. General parallel programing would also include SIMD systems (like your GPU),