franz1981 commented on a change in pull request #2645: ARTEMIS-2321 Paging
scalability and GC improvement
URL: https://github.com/apache/activemq-artemis/pull/2645#discussion_r279864970
##########
File path:
artemis-server/src/main/java/org/apache/activemq/artemis/core/paging/cursor/impl/PageCursorProviderImpl.java
##########
@@ -132,43 +156,88 @@ public PagedReference newReference(final PagePosition
pos,
@Override
public PageCache getPageCache(final long pageId) {
try {
+ if (pageId > pagingStore.getCurrentWritingPage()) {
+ return null;
+ }
+ boolean createPage = false;
+ CompletableFuture<PageCache> inProgressReadPage;
PageCache cache;
+ Page page = null;
synchronized (softCache) {
- if (pageId > pagingStore.getCurrentWritingPage()) {
+ cache = softCache.get(pageId);
+ if (cache != null) {
+ return cache;
+ }
+ if (!pagingStore.checkPageFileExists((int) pageId)) {
return null;
}
-
- cache = softCache.get(pageId);
- if (cache == null) {
- if (!pagingStore.checkPageFileExists((int) pageId)) {
- return null;
- }
-
+ inProgressReadPage = inProgressReadPages.get(pageId);
+ if (inProgressReadPage == null) {
+ final CompletableFuture<PageCache> readPage = new
CompletableFuture<>();
cache = createPageCache(pageId);
- // anyone reading from this cache will have to wait reading to
finish first
- // we also want only one thread reading this cache
- logger.tracef("adding pageCache pageNr=%d into cursor = %s",
pageId, this.pagingStore.getAddress());
- readPage((int) pageId, cache);
- softCache.put(pageId, cache);
+ page = pagingStore.createPage((int) pageId);
+ createPage = true;
+ inProgressReadPage = readPage;
+ inProgressReadPages.put(pageId, readPage);
}
}
+ //We need to create a new criticalComponent each time, because
+ //each read page action can happen from a different thread
+ final CriticalComponent readPageActionComponent;
+ if (criticalAnalyzer == null) {
+ readPageActionComponent = null;
+ } else {
+ final SimpleString address = pagingStore.getAddress();
+ readPageActionComponent = new
CriticalComponentImpl(criticalAnalyzer, PAGE_CURSOR_PROVIDER_CRITICAL_PATHS) {
Review comment:
I wasn't sure about it because you can have several concurrent
enterCritical() calls on the same component,while I want the critical analyser
to report which pageId read was too slow...
Wdyt?
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
us...@infra.apache.org
With regards,
Apache Git Services
