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[Home](https://www.msaied.com/public) 2. / 3. [Articles](https://www.msaied.com/public/articles) 4. / 5. Read/Write Splitting, Connection Pooling, and Sticky Reads in Laravel Read/Write Splitting, Connection Pooling, and Sticky Reads in Laravel ====================================================================== Learn how Laravel's database manager handles read/write connections, where sticky reads prevent stale data after writes, and how to layer PgBouncer or ProxySQL without breaking your application. ![](https://cdn.msaied.com/01M22N44A70A5MC2S599JP0MPH.webp) [Mohamed Said](https://www.msaied.com/public#person) Published 2 Aug 2026 · Updated 2 Aug 2026 · 4 min read ShareCopy linkCopied ![Read/Write Splitting, Connection Pooling, and Sticky Reads in Laravel](https://cdn.msaied.com/498/f6ccf4726d4e604ec0b53e696cb10551.png) On this page +1. [Read/Write Splitting, Connection Pooling, and Sticky Reads in Laravel](#readwrite-splitting-connection-pooling-and-sticky-reads-in-laravel) 2. [How Laravel Splits Reads and Writes](#how-laravel-splits-reads-and-writes) 3. [The sticky Option and Why It Matters](#the-codestickycode-option-and-why-it-matters) 4. [Forcing a Connection Explicitly](#forcing-a-connection-explicitly) 5. [Connection Pooling: PgBouncer and ProxySQL](#connection-pooling-pgbouncer-and-proxysql) 6. [Detecting Replica Lag in Application Code](#detecting-replica-lag-in-application-code) 7. [Takeaways](#takeaways) Read/Write Splitting, Connection Pooling, and Sticky Reads in Laravel --------------------------------------------------------------------- Scaling a Laravel application's database layer is rarely about raw query optimisation alone. At some point you add a read replica, and suddenly a whole class of subtle bugs appears: a user creates a record, gets redirected, and sees an empty list because the replica hasn't caught up yet. Understanding how Laravel's database manager handles this — and where it can silently betray you — is essential before you put a replica in front of real traffic. ### How Laravel Splits Reads and Writes Laravel's `DatabaseManager` accepts a `read` / `write` key inside any connection config. Each key accepts an array of hosts, and Laravel picks one at random per request. ```php // config/database.php 'pgsql' => [ 'driver' => 'pgsql', 'read' => [ 'host' => [ env('DB_READ_HOST_1', '10.0.1.11'), env('DB_READ_HOST_2', '10.0.1.12'), ], ], 'write' => [ 'host' => env('DB_WRITE_HOST', '10.0.1.10'), ], 'sticky' => true, 'database' => env('DB_DATABASE', 'app'), 'username' => env('DB_USERNAME'), 'password' => env('DB_PASSWORD'), 'charset' => 'utf8', 'prefix' => '', 'schema' => 'public', ], ``` Every `SELECT` goes to a read host; every `INSERT`, `UPDATE`, `DELETE`, and DDL statement goes to the write host. The split happens inside `Illuminate\Database\Connection::select()` and `statement()` — not at the Eloquent layer, so raw queries respect it too. ### The `sticky` Option and Why It Matters When `sticky` is `true`, Laravel records that a write occurred during the current request. Any subsequent read in the **same request lifecycle** is then routed to the write connection instead of a replica. ```php // Internally, Connection tracks this flag: protected $recordsModified = false; // After any write: $this->recordsModified = true; // On the next select, if sticky and recordsModified: return $this->getWritePdo(); ``` This prevents the classic post-write stale-read bug within a single HTTP request. It does **not** help across requests (e.g., a redirect after a form POST) — for that you need application-level logic or a short-circuit cache. ### Forcing a Connection Explicitly Sometimes you need deterministic routing regardless of `sticky`: ```php // Force read replica $users = DB::connection('pgsql')->table('users') ->useReadPdo() ->get(); // Force primary $user = User::on('pgsql')->find($id); // always write host // Or via the query builder: DB::table('orders')->useWritePdo()->where('id', $id)->first(); ``` `useReadPdo()` and `useWritePdo()` are available on the query builder and let you override sticky behaviour for a specific query. ### Connection Pooling: PgBouncer and ProxySQL Laravel opens a new PDO connection per worker process (or per request under FPM). At scale this exhausts `max_connections` on PostgreSQL quickly. PgBouncer in **transaction pooling** mode is the standard fix for Postgres. **Critical caveat:** transaction pooling breaks any feature that relies on session-level state — `SET LOCAL`, advisory locks, `pg_temp` tables, and `PREPARE` statements. Laravel's `DB::transaction()` is safe because PgBouncer keeps the same backend connection for the duration of a transaction block. Named prepared statements are **not** safe; disable them: ```php // config/database.php — disable server-side prepared statements 'pgsql' => [ // ... 'options' => [ PDO::ATTR_EMULATE_PREPARES => true, ], ], ``` For MySQL, ProxySQL can split reads and writes at the proxy layer based on query rules, which means you can point Laravel at a single host and let ProxySQL handle routing. This simplifies config but adds an infrastructure dependency. ### Detecting Replica Lag in Application Code If your workload is write-heavy and replica lag is unpredictable, consider a health-check approach: ```php // A simple lag guard using a heartbeat table public function replicaIsAcceptable(): bool { $lag = DB::connection('pgsql') ->table('replication_heartbeat') ->useReadPdo() ->value('lag_seconds'); return $lag !== null && $lag < 2; } ``` Update `replication_heartbeat` from a scheduled job every second on the primary. If lag exceeds your threshold, route critical reads to the write host for that request. ### Takeaways - Laravel's `read`/`write` config splits connections automatically; `sticky` prevents stale reads within a single request but not across requests. - Use `useReadPdo()` / `useWritePdo()` for explicit per-query routing. - PgBouncer transaction pooling requires `PDO::ATTR_EMULATE_PREPARES => true` to avoid named prepared statement errors. - ProxySQL can absorb the routing logic entirely, but adds a network hop and operational complexity. - Monitor replica lag actively; don't assume `sticky` is a complete solution for post-redirect reads. - [laravel](https://www.msaied.com/public/articles?search=laravel) - [database](https://www.msaied.com/public/articles?search=database) - [performance](https://www.msaied.com/public/articles?search=performance) - [postgresql](https://www.msaied.com/public/articles?search=postgresql) - [mysql](https://www.msaied.com/public/articles?search=mysql) Frequently asked questions --------------------------- Does Laravel's `sticky` option protect against stale reads after a redirect?No. `sticky` only routes reads to the write host within the same request lifecycle. After a redirect, a new request starts with a clean state and may hit a replica. You need a short-circuit cache, a heartbeat check, or explicit `useWritePdo()` calls for post-redirect reads on critical data. Why do I get 'prepared statement already exists' errors with PgBouncer?PgBouncer in transaction pooling mode reuses backend connections across clients, so named prepared statements created by one client can conflict with another. Set `PDO::ATTR\_EMULATE\_PREPARES => true` in your connection options to make PDO use client-side parameter interpolation instead of server-side prepared statements. Can I use multiple read replicas with different weights in Laravel?Laravel picks a read host uniformly at random from the `read.host` array. There is no built-in weighting. For weighted routing you need a proxy layer (ProxySQL, HAProxy) in front of Laravel, or a custom `DatabaseManager` binding that overrides `getReadPdo()` with your own selection logic. ![Mohamed Said](https://cdn.msaied.com/01M22N44A70A5MC2S599JP0MPH.webp)About the author ---------------- [Mohamed Said](https://www.msaied.com/public#person)Senior Backend Engineer specializing in Laravel, scalable SaaS platforms, APIs, and cloud infrastructure. I build secure, high-performance web applications that help businesses grow. [About](https://www.msaied.com/public#about) [GitHub ↗](https://github.com/EG-Mohamed) [LinkedIn ↗](https://www.linkedin.com/in/msaiedm/) [WhatsApp ↗](https://wa.me/201094619204) [Email Address ↗](mailto:hello@msaied.com) [My CV ↗](https://drive.google.com/file/u/0/d/1MF20IPRJyzfy32mhEutjL5EpSls0w2Q8/view) [Previous articleLaravel Service Container: Contextual Binding, Tagging, and Method Injection](https://www.msaied.com/public/articles/laravel-service-container-contextual-binding-tagging-and-method-injection-3) [Next articleLaravel Pipeline Pattern: Building Custom Pipelines Beyond Middleware](https://www.msaied.com/public/articles/laravel-pipeline-pattern-building-custom-pipelines-beyond-middleware-2) On this page ------------- 1. [Read/Write Splitting, Connection Pooling, and Sticky Reads in Laravel](#readwrite-splitting-connection-pooling-and-sticky-reads-in-laravel) 2. [How Laravel Splits Reads and Writes](#how-laravel-splits-reads-and-writes) 3. [The sticky Option and Why It Matters](#the-codestickycode-option-and-why-it-matters) 4. [Forcing a Connection Explicitly](#forcing-a-connection-explicitly) 5. [Connection Pooling: PgBouncer and ProxySQL](#connection-pooling-pgbouncer-and-proxysql) 6. [Detecting Replica Lag in Application Code](#detecting-replica-lag-in-application-code) 7. [Takeaways](#takeaways) ### Have a technical challenge? Tell me what you’re building. I reply within two working days. 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