ClickHouse Instrumentation inadvertently changes application code path

[cleverchuk]

Describe the bug

Execution of this line of code causes ClickHouse syntax error for queries of the form select * from table where s={s:String}. When that line is executed, it causes subsequent application code execution to follow a different code path which results in the error observed. There are two code paths to follow, this and this. When the first path is followed, the code executes normally and fails when the second path is followed due to the execution of this making preparedQuery not null.

Steps to reproduce

Add below test to ClickHouseClientTest

    @Test
    void testPlaceholderQueryInput() throws Exception {
        ClickHouseRequest<?> request = client.read(server).format(ClickHouseFormat.RowBinaryWithNamesAndTypes);
        testing.runWithSpan(
                "parent",
                () -> {
                    ClickHouseResponse response =
                            request
                                    .query("select * from " + tableName + " where s={s:String}")
                                    .settings(ImmutableMap.of("param_s", "" + Instant.now().getEpochSecond()))
                                    .execute().get();
                    response.close();

                });

        testing.waitAndAssertTraces(
                trace ->
                        trace.hasSpansSatisfyingExactly(
                                span -> span.hasName("parent").hasNoParent().hasAttributes(Attributes.empty()),
                                span ->
                                        span.hasName("SELECT " + dbName)
                                                .hasKind(SpanKind.CLIENT)
                                                .hasParent(trace.getSpan(0))
                                                .hasAttributesSatisfyingExactly(
                                                        attributeAssertions(
                                                                "select * from " + tableName + " where s={s:String}", "SELECT"))));
    }

Expected behavior

No syntax error

Actual behavior

Syntax error

Caused by: java.io.IOException: Code: 62. DB::Exception: Syntax error: failed at position 40 ('}'): }. Expected colon between name and type. (SYNTAX_ERROR) (version 24.4.2.141 (official build))

	at com.clickhouse.client.http.ApacheHttpConnectionImpl.checkResponse(ApacheHttpConnectionImpl.java:209)
	at com.clickhouse.client.http.ApacheHttpConnectionImpl.post(ApacheHttpConnectionImpl.java:243)
	at com.clickhouse.client.http.ClickHouseHttpClient.send(ClickHouseHttpClient.java:118)
	at com.clickhouse.client.AbstractClient.sendAsync(AbstractClient.java:161)
	at com.clickhouse.client.AbstractClient.lambda$execute$0(AbstractClient.java:273)
	... 98 more

Javaagent or library instrumentation version

2.9.0

Environment

JDK: openjdk 17.0.7
OS: OSX 24.2.0

Additional context

No response

[steverao]

Caused by: java.io.IOException: Code: 62. DB::Exception: Syntax error: failed at position 40 ('}'): }. Expected colon between name and type. (SYNTAX_ERROR) (version 24.4.2.141 (official build))

at com.clickhouse.client.http.ApacheHttpConnectionImpl.checkResponse(ApacheHttpConnectionImpl.java:209)
at com.clickhouse.client.http.ApacheHttpConnectionImpl.post(ApacheHttpConnectionImpl.java:243)
at com.clickhouse.client.http.ClickHouseHttpClient.send(ClickHouseHttpClient.java:118)
at com.clickhouse.client.AbstractClient.sendAsync(AbstractClient.java:161)
at com.clickhouse.client.AbstractClient.lambda$execute$0(AbstractClient.java:273)
... 98 more

From above error stacktrace, it seems come from ClickHouse itself instead of OTel Java Agent. The error message you are encountering, Expected colon between name and type, indicates that the syntax of your query is not correct. Specifically, ClickHouse expects a colon : between the parameter name and its type in the placeholder.
In your query:

"select * from " + tableName + " where s={s:String}"

You have used {s:String} which is incorrect. The correct syntax should be {s: String} with a space after the colon.
I found that the syntax error is resolved by above modification.
I found the related examples contain a space after the colon in documentation of ClickHouse, even though it doesn't seem to emphasize this point explicitly.

[laurit]

I think we can consider this as a bug in the instrumentation. Ideally code that runs without the agent should also run with the agent, even when there really is a small syntax error in the query.