From 7a59f46f33c7c8200b067be258e051e83cdf4608 Mon Sep 17 00:00:00 2001
From: Gilles Filippini <pini@debian.org>
Date: Fri, 14 May 2021 02:44:45 +0200
Subject: [PATCH] fix(sync): don't lose nodes on single download err
`P2pCandidate.dlPromise` promise doesn't resolve on download errors
such as socket timeouts. Each time such an error occurs, the node is lost
for the sync because the 'this.dlPromise.isResolved()' check used for
testing the node's availability never succeeds anymore for this node.
This patch hardens the blocks downloading in two ways:
* Retrying the download up to 5 times when the number of returned blocks is
different from what was requested
* On failure returns an empty block array so that the dlPromise is resolved
and the node failure could be handled as expected at the P2PSyncDownloader
level triggering the `P2pCandidate.addFailure()` function.
---
.../crawler/lib/sync/p2p/p2p-candidate.ts | 29 ++++++++++++-------
1 file changed, 19 insertions(+), 10 deletions(-)
diff --git a/app/modules/crawler/lib/sync/p2p/p2p-candidate.ts b/app/modules/crawler/lib/sync/p2p/p2p-candidate.ts
index 8f81ed886..6b6403bbc 100644
--- a/app/modules/crawler/lib/sync/p2p/p2p-candidate.ts
+++ b/app/modules/crawler/lib/sync/p2p/p2p-candidate.ts
@@ -90,21 +90,30 @@ export class P2pCandidate {
this.dlPromise = querablep(
(async () => {
// We try to download the blocks
- let blocks: BlockDTO[] | null;
- try {
- blocks = await (this.api as IRemoteContacter).getBlocks(count, from);
- } catch (e) {
- // Unfortunately this can fail
- blocks = null;
- error = e;
+ let blocks: BlockDTO[] = [];
+ let tries = 5;
+ while (tries > 0) {
+ try {
+ blocks = await (this.api as IRemoteContacter).getBlocks(
+ count,
+ from
+ );
+ } catch (e) {
+ // Unfortunately this can fail
+ blocks = [];
+ this.logger.error(e);
+ }
+ if (blocks.length != count) {
+ this.logger.error("Wrong number of blocks from %s", this.hostName);
+ tries--;
+ } else {
+ break;
+ }
}
this.responseTimes.push(Date.now() - start);
// Only keep a flow of 5 ttas for the node
if (this.responseTimes.length > 5) this.responseTimes.shift();
this.nbSuccess++;
- if (error) {
- throw error;
- }
return blocks;
})()
);
--
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