{"record":{"id":"8d8a3fffc69de4ab","repo":"nautechsystems/nautilus_trader","slug":"failed-to-connect-to-the-postgres-cache-database","errorCode":null,"errorMessage":"Failed to connect to the Postgres cache database: {e}","messagePattern":"Failed to connect to the Postgres cache database: (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"critical","filePath":"crates/adapters/blockchain/src/execution/client.rs","lineNumber":5883,"sourceCode":"        if self.cache.database.is_some() || self.config.postgres_cache_database_config.is_some() {\n            let keys = payload_keys.as_deref().ok_or_else(|| {\n                anyhow::anyhow!(\n                    \"Postgres execution requires an active payload key and deployment identity\"\n                )\n            })?;\n\n            if self.cache.database.is_none() {\n                let pg_options = self\n                    .config\n                    .postgres_cache_database_config\n                    .as_ref()\n                    .expect(\"Postgres configuration checked above\");\n                let database = crate::cache::database::BlockchainCacheDatabase::connect(\n                    pg_options.clone().into(),\n                )\n                .await\n                .map_err(|e| {\n                    anyhow::anyhow!(\"Failed to connect to the Postgres cache database: {e}\")\n                })?;\n                self.cache.database = Some(database);\n            }\n            self.cache\n                .database\n                .as_ref()\n                .expect(\"database was attached\")\n                .require_execution_payload_storage_ready(keys)\n                .await?;\n            self.cache.initialize_chain().await;\n            self.cache.ensure_execution_transaction_schema().await?;\n            let check = self\n                .cache\n                .database\n                .as_ref()\n                .expect(\"database was attached\")\n                .check_execution_payload_storage(\n                    Some(keys),","sourceCodeStart":5865,"sourceCodeEnd":5901,"githubUrl":"https://github.com/nautechsystems/nautilus_trader/blob/18893faf8b356be3320add8de2f861b0b647cf06/crates/adapters/blockchain/src/execution/client.rs#L5865-L5901","documentation":"The client lazily connects to the configured Postgres cache database via BlockchainCacheDatabase::connect during setup. If the connection cannot be established, the error is wrapped as \"Failed to connect to the Postgres cache database\". This is a hard failure because durable payload storage is mandatory for Postgres-backed execution.","triggerScenarios":"Startup with postgres_cache_database_config set where the TCP/TLS connection to Postgres fails, credentials are rejected, the database/host is wrong, or the server is unreachable/overloaded.","commonSituations":"Wrong host/port in the cache database config; firewall or security group blocking the port; expired or rotated DB credentials; Postgres down or at max_connections; TLS certificate mismatch; DNS resolution failure in containerized deployments.","solutions":["Check the inner error {e} to distinguish DNS/refused/auth/TLS failures and fix accordingly","Verify postgres_cache_database_config host, port, database, user, and password against the actual Postgres instance","Test connectivity from the same host/network (psql or pg_isready) to rule out firewalls and DNS issues","Confirm the Postgres server is running and accepting connections (max_connections, logs), then retry startup"],"exampleFix":"// before\npostgres_cache_database_config = Some(PgConfig { host: \"db.internal\", port: 5432, ... })\n// after (verified reachable & credentials valid)\npostgres_cache_database_config = Some(PgConfig { host: \"db.internal\", port: 5433, user: \"nautilus\", password: <from secret>, ssl_mode: require })","handlingStrategy":"retry","validationCode":"// preflight connectivity check before startup\nlet res = tokio::net::TcpStream::connect((host, port)).await;\nassert!(res.is_ok(), \"Postgres host {host}:{port} unreachable\");","typeGuard":null,"tryCatchPattern":"// wrap connect with bounded retries\nfor attempt in 1..=3 {\n    match try_start_client(config.clone()).await {\n        Err(e) if e.to_string().contains(\"Failed to connect to the Postgres cache database\") => {\n            log::warn!(\"pg connect failed (attempt {attempt}): {e}\");\n            tokio::time::sleep(Duration::from_secs(2u64.pow(attempt))).await;\n        }\n        other => { other?; break; }\n    }\n}","preventionTips":["Run pg_isready/psql connectivity checks in deployment health probes before starting the client","Load DB credentials from a secret manager and rotate without downtime","Configure TLS and verify certificates match the Postgres host","Set sane pool limits so the client doesn't exhaust max_connections"],"tags":["postgres","database","connectivity","startup"],"backgroundTag":"connection-refused","analyzedSha":"18893faf8b356be3320add8de2f861b0b647cf06","analyzedAt":"2026-09-08T20:49:34.690Z","contentChangedAt":"2026-09-08T20:49:34.690Z","schemaVersion":2},"datasetVersion":"2026-09-14T05:17:10.506Z"}