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https://issues.apache.org/jira/browse/ACCUMULO-4837?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Keith Turner resolved ACCUMULO-4837.
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Resolution: Duplicate
https://github.com/apache/accumulo/issues/1124
> Allow short service names in addition to class names.
> -----------------------------------------------------
>
> Key: ACCUMULO-4837
> URL: https://issues.apache.org/jira/browse/ACCUMULO-4837
> Project: Accumulo
> Issue Type: Improvement
> Reporter: Keith Turner
> Priority: Major
>
> In 2.0.0-SNAPSHOT the cache implementation was made configurable. Currently
> to configure it, you set a property like the following.
> {noformat}
>
> tserver.cache.manager.class=org.apache.accumulo.core.file.blockfile.cache.tinylfu.TinyLfuBlockCacheManager
> {noformat}
> I would much rather be able to provide a short service name like the
> following when configuring the cache. However I do not want the list to be
> predefined, I will want the user to be able to provide implementations.
> {noformat}
> tserver.cache.implementation=tinylfu
> {noformat}
> What is a good way to do this? Is there a good reason not do this and just
> stick with class names only? I was also thinking it may be nice to have a
> shell command for listing services, but this could be done independently.
> One way I thought of doing this is having an interface like the the following
> that services (balancer, compaction strategy, cache, etc) could implement.
> {code:java}
> public interface AccumuloService {
> /**
> * A human readable, short, unique identification that can be specified in
> configuration to identify a service implementation.
> */
> public String getName();
> public static <C extends AccumuloService> C load(String configId, Class<C>
> serviceType, ClassLoader classLoader) {
> ServiceLoader<C> services = ServiceLoader.load(serviceType, classLoader);
> for (C service : services) {
> if(service.getName().equals(configId) ||
> service.getClass().getName().equals(configId)) {
> return service;
> }
> }
> return null;
> }
> }
> {code}
> Then the cache implementation could provide a name
> {code:java}
> //assume BlockCacheManager implements AccumuloService
> public class TinyLfuBlockCacheManager extends BlockCacheManager {
> private static final Logger LOG =
> LoggerFactory.getLogger(TinyLfuBlockCacheManager.class);
> @Override
> protected TinyLfuBlockCache createCache(Configuration conf, CacheType type)
> {
> LOG.info("Creating {} cache with configuration {}", type, conf);
> return new TinyLfuBlockCache(conf, type);
> }
> @Override
> public String getName() {
> return "tinylfu";
> }
> }
> {code}
> The code to load a block cache impl would look like the following :
> {code:java}
> String impl = conf.get(Property.TSERV_CACHE_MANAGER_IMPL);
> BlockCacheManager bcm = AccumuloService.load(impl,
> BlockCacheManager.class, AccumuloVFSClassLoader.getClassLoader());
> {code}
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