Description
client-v2 depends on zstd-jni with the cloud classifier
(client-v2/pom.xml:61-66):
<dependency>
<groupId>com.github.luben</groupId>
<artifactId>zstd-jni</artifactId>
<version>1.5.7-20</version>
<classifier>cloud</classifier>
</dependency>
The cloud classifier jar contains native libraries for only three platforms:
darwin/aarch64/libzstd-jni-1.5.7-20.dylib
linux/aarch64/libzstd-jni-1.5.7-20.so
linux/amd64/libzstd-jni-1.5.7-20.so
There is no win/* and no darwin/x86_64. The default zstd-jni artifact of the same
version contains 18 natives, including win/amd64, win/x86, win/aarch64 and
darwin/x86_64.
Because ClientConfigProperties.COMPRESSION_METHOD defaults to CompressionMethod.ZSTD
(ClientConfigProperties.java:104),
ZSTD is not an opt-in path. On Windows and on Intel macOS, client-v2 and jdbc-v2 fail on
the first query with default settings — the class initializer for
com.github.luben.zstd.Zstd throws, and every subsequent call fails with
NoClassDefFoundError.
Steps to reproduce
On Windows x86-64, against a server new enough to return ZSTD-compressed blocks (26.x):
try (Connection conn = DriverManager.getConnection("jdbc:clickhouse://localhost:8123/", "default", "");
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("SELECT 1")) {
rs.next();
}
No compression setting is applied — this is the default configuration.
Equivalently, mvn -pl jdbc-v2 verify -Dit.test=DatabaseMetaDataTest on Windows against the
latest image gives 44 of 47 failures, all from this one cause. The same command with
-DclickhouseVersion=25.8 passes 47/47, because that server does not send ZSTD blocks.
Error Log or Exception StackTrace
First failure — the class initializer:
java.lang.UnsatisfiedLinkError:
Failed to open resource /win/amd64/libzstd-jni-1.5.7-20.dll as stream:
Unsupported OS/arch, cannot find /win/amd64/libzstd-jni-1.5.7-20.dll or load zstd-jni-1.5.7-20
from system libraries. Please try building from source the jar or providing
libzstd-jni-1.5.7-20 in your system.
at com.github.luben.zstd.util.Native.load(Native.java:124)
at com.github.luben.zstd.util.Native.load(Native.java:93)
at com.github.luben.zstd.Zstd.<clinit>(Zstd.java:22)
at com.clickhouse.client.api.internal.CompressedBlockInputStream.refill(CompressedBlockInputStream.java:156)
at com.clickhouse.client.api.internal.CompressedBlockInputStream.read(CompressedBlockInputStream.java:63)
at com.clickhouse.client.api.data_formats.internal.BinaryStreamReader.readByteOrEOF(BinaryStreamReader.java:1555)
at com.clickhouse.client.api.data_formats.RowBinaryWithNamesAndTypesFormatReader.readSchema(RowBinaryWithNamesAndTypesFormatReader.java:41)
at com.clickhouse.client.api.Client.newBinaryFormatReader(Client.java:2451)
at com.clickhouse.jdbc.StatementImpl.executeQueryImpl(StatementImpl.java:325)
Every later query in the same JVM:
java.lang.NoClassDefFoundError: Could not initialize class com.github.luben.zstd.Zstd
at com.clickhouse.client.api.internal.CompressedBlockInputStream.refill(CompressedBlockInputStream.java:156)
...
Expected Behaviour
The default configuration should work on every platform the driver supports. A JDBC driver
that cannot run SELECT 1 on Windows out of the box is unusable there, and the failure
surfaces as NoClassDefFoundError rather than anything a user can act on.
Root cause
Introduced in 9dc6a95 ("Added ZSTD block compression support"), merged as #3157, which
fixed #3105 and #3120. Those fixes are correct; only the choice of classifier is the
problem here. The
cloud classifier is published by zstd-jni for deployments that only ever run on Linux or
Apple-silicon containers; it is a size optimisation (1.0 MB vs 6.5 MB) and is not suitable
for a general-purpose client library.
Note that clickhouse-data, clickhouse-http-client and clickhouse-jdbc already depend
on the default zstd-jni artifact through dependencyManagement
(${zstd-jni.version}, currently 1.5.5-5, no classifier), so client-v2 is the only module
using the restricted jar, and it also pins its own version instead of the managed one.
Suggested fix
Preferred — drop the classifier and use the managed version, so the module matches the rest
of the project:
<dependency>
<groupId>com.github.luben</groupId>
<artifactId>zstd-jni</artifactId>
</dependency>
with <zstd-jni.version> in the parent raised to 1.5.7-20. Cost is roughly 5.5 MB of jar
size; correctness on Windows and Intel macOS seems worth that, and users who need the small
jar can still exclude it and substitute the cloud artifact themselves.
Independently of the dependency choice, CompressedBlockInputStream could fail more
usefully: catching UnsatisfiedLinkError / NoClassDefFoundError when ZSTD is first
touched and reporting that the native library is missing for this platform — naming the
compression.method setting — would turn an opaque NoClassDefFoundError into something
actionable, and would protect against the same class of problem in future.
A regression test would need a non-Linux runner; the CI matrix is Linux-only, which is why
this was not caught. At minimum, a unit test asserting that the resolved zstd-jni artifact
contains win/amd64 would catch a reintroduction without needing a Windows runner.
Configuration
Environment
ClickHouse Server
- ClickHouse Server version:
clickhouse/clickhouse-server:latest via Testcontainers
- ClickHouse Server non-default settings, if any: none
Description
client-v2depends onzstd-jniwith thecloudclassifier(
client-v2/pom.xml:61-66):The
cloudclassifier jar contains native libraries for only three platforms:There is no
win/*and nodarwin/x86_64. The defaultzstd-jniartifact of the sameversion contains 18 natives, including
win/amd64,win/x86,win/aarch64anddarwin/x86_64.Because
ClientConfigProperties.COMPRESSION_METHODdefaults toCompressionMethod.ZSTD(
ClientConfigProperties.java:104),ZSTD is not an opt-in path. On Windows and on Intel macOS,
client-v2andjdbc-v2fail onthe first query with default settings — the class initializer for
com.github.luben.zstd.Zstdthrows, and every subsequent call fails withNoClassDefFoundError.Steps to reproduce
On Windows x86-64, against a server new enough to return ZSTD-compressed blocks (26.x):
No compression setting is applied — this is the default configuration.
Equivalently,
mvn -pl jdbc-v2 verify -Dit.test=DatabaseMetaDataTeston Windows against thelatestimage gives 44 of 47 failures, all from this one cause. The same command with-DclickhouseVersion=25.8passes 47/47, because that server does not send ZSTD blocks.Error Log or Exception StackTrace
First failure — the class initializer:
Every later query in the same JVM:
Expected Behaviour
The default configuration should work on every platform the driver supports. A JDBC driver
that cannot run
SELECT 1on Windows out of the box is unusable there, and the failuresurfaces as
NoClassDefFoundErrorrather than anything a user can act on.Root cause
Introduced in 9dc6a95 ("Added ZSTD block compression support"), merged as #3157, which
fixed #3105 and #3120. Those fixes are correct; only the choice of classifier is the
problem here. The
cloudclassifier is published by zstd-jni for deployments that only ever run on Linux orApple-silicon containers; it is a size optimisation (1.0 MB vs 6.5 MB) and is not suitable
for a general-purpose client library.
Note that
clickhouse-data,clickhouse-http-clientandclickhouse-jdbcalready dependon the default
zstd-jniartifact throughdependencyManagement(
${zstd-jni.version}, currently 1.5.5-5, no classifier), soclient-v2is the only moduleusing the restricted jar, and it also pins its own version instead of the managed one.
Suggested fix
Preferred — drop the classifier and use the managed version, so the module matches the rest
of the project:
with
<zstd-jni.version>in the parent raised to1.5.7-20. Cost is roughly 5.5 MB of jarsize; correctness on Windows and Intel macOS seems worth that, and users who need the small
jar can still exclude it and substitute the
cloudartifact themselves.Independently of the dependency choice,
CompressedBlockInputStreamcould fail moreusefully: catching
UnsatisfiedLinkError/NoClassDefFoundErrorwhen ZSTD is firsttouched and reporting that the native library is missing for this platform — naming the
compression.methodsetting — would turn an opaqueNoClassDefFoundErrorinto somethingactionable, and would protect against the same class of problem in future.
A regression test would need a non-Linux runner; the CI matrix is Linux-only, which is why
this was not caught. At minimum, a unit test asserting that the resolved
zstd-jniartifactcontains
win/amd64would catch a reintroduction without needing a Windows runner.Configuration
Environment
0.11.0-rc1-SNAPSHOT(mainat 16dcde4)ClickHouse Server
clickhouse/clickhouse-server:latestvia Testcontainers