Hi,
in general you can still use MMapDirectory. There is no requirement to
set vm.max_map_count for smaller clusters. The information in Elastics
documentation is not mandatory and misleading.
If you use newest version of Elasticsearch with Java 19 and you use
`--enable-preview` in you jvm.properties file, you don't even need to
change that setting even with larger clusters.
Uwe
Am 02.01.2023 um 11:18 schrieb S S:
We are experimenting with Elastic Search deployed in Azure Container Instances
(Debian + OpenJDK). The ES indexes are stored into an Azure file share mounted
via SMB (3.0). The Elastic Search cluster is made up of 4 nodes, each one have
a separate file share to store the indices.
This configuration has been influenced by some ACIs limitations, specifically:
we cannot set the max_map_count value as we do not have access to the
underlying host
(https://www.elastic.co/guide/en/elasticsearch/reference/current/vm-max-map-count.html).
Unfortunately, this is required to run an ES cluster, therefore we were forced
to use NIOF
ACI’s storage is ephemera, therefore we had to map volumes to persist the
indexes. ACIs only allow volume mappings using Azure File Shares, which only
works with NFS or SMB.
We are experiencing recurring index corruption, specifically a "read past EOF"
exception. I asked on the Elastic Search forum but the answer I got was a bit generic and
not really helpful other than confirming that, from ES point of view, ES should work on
an SMB share as long as it behaves as a local drive. As the underlying exception relates
to an issue with a Lucene index, I was wondering if you could help out? Specifically, can
Lucene work on SMB? I can only find sparse information on this configuration and, while
NFS seems a no-no, for SMB is not that clear. Below is the exception we are getting.
java.io.IOException: read past EOF:
NIOFSIndexInput(path="/bitnami/elasticsearch/data/indices/mS2bUbLtSeG0FSAMuKX7JQ/0/index/_ldsn_1.fnm")
buffer: java.nio.HeapByteBuffer[pos=0 lim=1024 cap=1024] chunkLen: 1024 end: 2331:
NIOFSIndexInput(path="/bitnami/elasticsearch/data/indices/mS2bUbLtSeG0FSAMuKX7JQ/0/index/_ldsn_1.fnm")
at
org.apache.lucene.store.NIOFSDirectory$NIOFSIndexInput.readInternal(NIOFSDirectory.java:200)
~[lucene-core-9.3.0.jar:?]
at
org.apache.lucene.store.BufferedIndexInput.refill(BufferedIndexInput.java:291)
~[lucene-core-9.3.0.jar:?]
at
org.apache.lucene.store.BufferedIndexInput.readByte(BufferedIndexInput.java:55)
~[lucene-core-9.3.0.jar:?]
at
org.apache.lucene.store.BufferedChecksumIndexInput.readByte(BufferedChecksumIndexInput.java:39)
~[lucene-core-9.3.0.jar:?]
at
org.apache.lucene.codecs.CodecUtil.readBEInt(CodecUtil.java:667)
~[lucene-core-9.3.0.jar:?]
at
org.apache.lucene.codecs.CodecUtil.checkHeader(CodecUtil.java:184)
~[lucene-core-9.3.0.jar:?]
at
org.apache.lucene.codecs.CodecUtil.checkIndexHeader(CodecUtil.java:253)
~[lucene-core-9.3.0.jar:?]
at
org.apache.lucene.codecs.lucene90.Lucene90FieldInfosFormat.read(Lucene90FieldInfosFormat.java:128)
~[lucene-core-9.3.0.jar:?]
at
org.apache.lucene.index.SegmentReader.initFieldInfos(SegmentReader.java:205)
~[lucene-core-9.3.0.jar:?]
at
org.apache.lucene.index.SegmentReader.<init>(SegmentReader.java:156)
~[lucene-core-9.3.0.jar:?]
at
org.apache.lucene.index.ReadersAndUpdates.createNewReaderWithLatestLiveDocs(ReadersAndUpdates.java:738)
~[lucene-core-9.3.0.jar:?]
at
org.apache.lucene.index.ReadersAndUpdates.swapNewReaderWithLatestLiveDocs(ReadersAndUpdates.java:754)
~[lucene-core-9.3.0.jar:?]
at
org.apache.lucene.index.ReadersAndUpdates.writeFieldUpdates(ReadersAndUpdates.java:678)
~[lucene-core-9.3.0.jar:?]
at
org.apache.lucene.index.ReaderPool.writeAllDocValuesUpdates(ReaderPool.java:251)
~[lucene-core-9.3.0.jar:?]
at
org.apache.lucene.index.IndexWriter.writeReaderPool(IndexWriter.java:3743)
~[lucene-core-9.3.0.jar:?]
at
org.apache.lucene.index.IndexWriter.getReader(IndexWriter.java:591)
~[lucene-core-9.3.0.jar:?]
at
org.apache.lucene.index.StandardDirectoryReader.doOpenFromWriter(StandardDirectoryReader.java:381)
~[lucene-core-9.3.0.jar:?]
at
org.apache.lucene.index.StandardDirectoryReader.doOpenIfChanged(StandardDirectoryReader.java:355)
~[lucene-core-9.3.0.jar:?]
at
org.apache.lucene.index.StandardDirectoryReader.doOpenIfChanged(StandardDirectoryReader.java:345)
~[lucene-core-9.3.0.jar:?]
at
org.apache.lucene.index.FilterDirectoryReader.doOpenIfChanged(FilterDirectoryReader.java:112)
~[lucene-core-9.3.0.jar:?]
at
org.apache.lucene.index.DirectoryReader.openIfChanged(DirectoryReader.java:170)
~[lucene-core-9.3.0.jar:?]
at
org.elasticsearch.index.engine.ElasticsearchReaderManager.refreshIfNeeded(ElasticsearchReaderManager.java:48)
~[elasticsearch-8.4.1.jar:?]
at
org.elasticsearch.index.engine.ElasticsearchReaderManager.refreshIfNeeded(ElasticsearchReaderManager.java:27)
~[elasticsearch-8.4.1.jar:?]
at
org.apache.lucene.search.ReferenceManager.doMaybeRefresh(ReferenceManager.java:167)
~[lucene-core-9.3.0.jar:?]
at
org.apache.lucene.search.ReferenceManager.maybeRefreshBlocking(ReferenceManager.java:240)
~[lucene-core-9.3.0.jar:?]
at
org.elasticsearch.index.engine.InternalEngine$ExternalReaderManager.refreshIfNeeded(InternalEngine.java:355)
~[elasticsearch-8.4.1.jar:?]
at
org.elasticsearch.index.engine.InternalEngine$ExternalReaderManager.refreshIfNeeded(InternalEngine.java:335)
~[elasticsearch-8.4.1.jar:?]
at
org.apache.lucene.search.ReferenceManager.doMaybeRefresh(ReferenceManager.java:167)
~[lucene-core-9.3.0.jar:?]
Many thanks.
Seb
--
Uwe Schindler
Achterdiek 19, D-28357 Bremen
https://www.thetaphi.de
eMail: u...@thetaphi.de
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