NationalSecurityAgency/ghidra · error · LSHException

Prewarm failed: {}

Error message

Prewarm failed: {}

What it means

Thrown in prewarm when ResponsePrewarm response is null, i.e. the server rejected the PrewarmRequest. BulkSignatures wraps the server's BSimError into 'Prewarm failed: <message>' (LSHException). A non-null response with operationSupported=false is logged as an error rather than thrown, so this throw specifically indicates a null protocol-level response.

Source

Thrown at Ghidra/Features/BSim/src/main/java/ghidra/features/bsim/query/ingest/BulkSignatures.java:656

		}
		else {
			Msg.info(this, "Successfully rebuilt index " + dbDetail);
		}
	}

	/**
	 * Performs a prewarm command on the BSim database.
	 * 
	 * @throws IOException if there's an error establishing the database connection
	 * @throws LSHException if there's an error issuing the query
	 */
	public void prewarm() throws IOException, LSHException {
		DatabaseInformation info = establishQueryServerConnection(false);
		PrewarmRequest request = new PrewarmRequest();
		ResponsePrewarm response = request.execute(querydb);
		if (response == null) {
			BSimError lastError = querydb.getLastError();
			throw new LSHException("Prewarm failed: " + lastError.message);
		}
		String dbDetail = "for database " + info.databasename + " (" + bsimServerInfo + ")";
		if (!response.operationSupported) {
			Msg.error(this, "Prewarm operation not supported " + dbDetail);
		}
		else {
			Msg.info(this, "Successfully prewarmed " + Integer.toString(response.blockCount) +
				" blocks of main index " + dbDetail);
		}
	}

	/**
	 * Returns a list of all executable records meeting a set of search criteria.
	 * 
	 * @param limit the maximum number of results to return
	 * @param md5Filter MD5 filter
	 * @param exeNameFilter executable name filter
	 * @param archFilter architecture filter

View on GitHub (pinned to d5f144c24d)

Solutions

1. Read the message to distinguish unsupported vs. transient failure.
2. Only call prewarm on backends that support it and after an index exists.
3. Retry on transient connection failures.
4. Check server logs if the cause is unclear.

Example fix

// before
bsim.prewarm();  // unsupported backend -> LSHException

// after
// only prewarm on a supported, populated backend

// only prewarm on supported, populated backends after an index exists

try {
    bsim.prewarm();
} catch (LSHException e) {
    // message: "Prewarm failed: <server>"; if unsupported, skip; if transient, retry
}

When it happens

Trigger: Prewarming a backend that rejects the request: unsupported storage engine returning null, connection failure, or no index/main table to prewarm.

Common situations: Prewarm is only meaningful for certain backends (e.g. PostgreSQL with an index); calling it on H2 or an unindexed DB can yield null; transient connection loss.

Related errors

• Could not drop index: {}
• Could not rebuild index: {}
• Could not perform delete: {}
• Could not perform getexeinfo: {}
• Could not change metadata: {}

AI-assisted analysis of NationalSecurityAgency/ghidra@d5f144c24d (2026-08-14). Data as JSON: /api/errors/aad44aec51823045. Report an issue: GitHub.