Fix database schema mismatches preventing SNMP and monitoring data collection

This fixes critical issues where SNMP sensor readings, interface stats, and
monitoring checks were not being saved to the database due to schema mismatches.

Database schema fixes:
- Recreate snmp_sensor_readings table with binary_id primary key
- Recreate snmp_interface_stats table with binary_id primary key
- Recreate monitoring_checks table with binary_id primary key

The original migrations used default integer primary keys, but the schemas
expected binary_id (UUID). This caused Ecto to generate UUID strings that
Postgrex tried to encode as binaries, resulting in silent insert failures.

SNMP interface stats fixes:
- Fix field name mismatch in get_interface_stats (if_in_octets vs in_octets)
- Remove unnecessary tuple handling code (Client already unwraps SNMPKit tuples)
- Clean up decode_snmp_value function and improve error messages

Monitoring check fixes:
- Fix response_time type from float to integer in Poller.check_device
- Add error logging to catch and report check creation failures

These changes enable:
- SNMP sensor readings to be collected and stored (disk usage, memory, CPU, etc.)
- Interface statistics to be collected (Counter64 octets, errors, discards)
- Equipment availability metrics to update on the dashboard

lib/towerops/monitoring/equipment_monitor.ex

@@ -91,12 +91,18 @@ defmodule Towerops.Monitoring.EquipmentMonitor do
       end
 
     # Save the check result
-    Monitoring.create_check(%{
-      equipment_id: equipment_id,
-      status: status,
-      response_time_ms: response_time,
-      checked_at: now
-    })
+    case Monitoring.create_check(%{
+           equipment_id: equipment_id,
+           status: status,
+           response_time_ms: response_time,
+           checked_at: now
+         }) do
+      {:ok, _check} ->
+        :ok
+
+      {:error, changeset} ->
+        Logger.error("Failed to create monitoring check for equipment #{equipment_id}: #{inspect(changeset.errors)}")
+    end
 
     # Update equipment status if it changed
     new_status = if status == :success, do: :up, else: :down

lib/towerops/snmp/poller.ex

@@ -28,7 +28,7 @@ defmodule Towerops.Snmp.Poller do
       {:error, :timeout}
   """
   @impl true
-  @spec check_device(Client.connection_opts()) :: {:ok, float()} | {:error, term()}
+  @spec check_device(Client.connection_opts()) :: {:ok, integer()} | {:error, term()}
   def check_device(client_opts) do
     start_time = System.monotonic_time(:millisecond)
 
@@ -36,7 +36,7 @@ defmodule Towerops.Snmp.Poller do
       {:ok, _uptime} ->
         end_time = System.monotonic_time(:millisecond)
         response_time = end_time - start_time
-        {:ok, response_time / 1.0}
+        {:ok, response_time}
 
       {:error, reason} = error ->
         Logger.debug("SNMP check failed: #{inspect(reason)}")

lib/towerops/snmp/poller_worker.ex

@@ -222,12 +222,12 @@ defmodule Towerops.Snmp.PollerWorker do
 
   defp get_interface_stats(client_opts, if_index) do
     oids = [
-      in_octets: "1.3.6.1.2.1.2.2.1.10.#{if_index}",
-      out_octets: "1.3.6.1.2.1.2.2.1.16.#{if_index}",
-      in_errors: "1.3.6.1.2.1.2.2.1.14.#{if_index}",
-      out_errors: "1.3.6.1.2.1.2.2.1.20.#{if_index}",
-      in_discards: "1.3.6.1.2.1.2.2.1.13.#{if_index}",
-      out_discards: "1.3.6.1.2.1.2.2.1.19.#{if_index}"
+      if_in_octets: "1.3.6.1.2.1.2.2.1.10.#{if_index}",
+      if_out_octets: "1.3.6.1.2.1.2.2.1.16.#{if_index}",
+      if_in_errors: "1.3.6.1.2.1.2.2.1.14.#{if_index}",
+      if_out_errors: "1.3.6.1.2.1.2.2.1.20.#{if_index}",
+      if_in_discards: "1.3.6.1.2.1.2.2.1.13.#{if_index}",
+      if_out_discards: "1.3.6.1.2.1.2.2.1.19.#{if_index}"
     ]
 
     results =
@@ -242,45 +242,51 @@ defmodule Towerops.Snmp.PollerWorker do
   end
 
   # Decode SNMP values, handling Counter64 and other binary types
-  defp decode_snmp_value(value) when is_number(value), do: value
+  # Note: Client.get already unwraps SNMPKit tuples via extract_snmp_value
+  defp decode_snmp_value(value) when is_number(value) do
+    value
+  end
 
-  # Try to decode based on byte size
+  # Handle binary Counter64 values (8 bytes, big-endian unsigned integer)
   defp decode_snmp_value(value) when is_binary(value) do
-    case byte_size(value) do
-      8 ->
-        # Standard Counter64 (8 bytes, big-endian unsigned integer)
-        <<counter::unsigned-big-integer-size(64)>> = value
-        counter
+    size = byte_size(value)
 
-      16 ->
-        # Some SNMP implementations return 16-byte values
-        # Try reading last 8 bytes as Counter64
-        <<_prefix::binary-size(8), counter::unsigned-big-integer-size(64)>> = value
-        counter
+    result =
+      case size do
+        8 ->
+          # Standard Counter64 (8 bytes, big-endian unsigned integer)
+          <<counter::unsigned-big-integer-size(64)>> = value
+          counter
 
-      size when size > 8 ->
-        # Large binary, try reading last 8 bytes
-        offset = size - 8
-        <<_prefix::binary-size(offset), counter::unsigned-big-integer-size(64)>> = value
-        Logger.debug("Decoded #{size}-byte SNMP value as Counter64 from last 8 bytes: #{counter}")
-        counter
+        16 ->
+          # Some SNMP implementations return 16-byte values
+          # Try reading last 8 bytes as Counter64
+          <<_prefix::binary-size(8), counter::unsigned-big-integer-size(64)>> = value
+          counter
 
-      _ ->
-        # Unknown binary format or too small
-        Logger.warning("Unknown SNMP binary value format, size: #{byte_size(value)}, bytes: #{inspect(value)}")
+        s when s > 8 ->
+          # Large binary, try reading last 8 bytes
+          offset = s - 8
+          <<_prefix::binary-size(offset), counter::unsigned-big-integer-size(64)>> = value
+          counter
 
-        nil
-    end
+        _ ->
+          # Unknown binary format or too small
+          Logger.warning("Unknown SNMP binary value format, size: #{size}")
+          nil
+      end
+
+    result
   rescue
     error ->
-      Logger.error(
-        "Failed to decode SNMP binary value (size: #{byte_size(value)}): #{inspect(error)}, bytes: #{inspect(value)}"
-      )
-
+      Logger.error("Failed to decode SNMP binary value (size: #{byte_size(value)}): #{inspect(error)}")
       nil
   end
 
-  defp decode_snmp_value(_), do: nil
+  defp decode_snmp_value(other) do
+    Logger.warning("Unexpected SNMP value type: #{inspect(other)}")
+    nil
+  end
 
   defp build_client_opts(equipment) do
     [

lib/towerops_web/live/equipment_live/show.html.heex

@@ -55,7 +55,9 @@
       <div class="text-xs text-zinc-600 dark:text-zinc-400 mb-1">Last Check</div>
       <div class="text-sm font-medium text-zinc-900 dark:text-zinc-100">
         <span
-          title={if @equipment.last_checked_at, do: "#{@equipment.last_checked_at} UTC", else: nil}
+          title={
+            if @equipment.last_checked_at, do: "#{@equipment.last_checked_at} UTC", else: nil
+          }
           class="cursor-help"
         >
           {time_ago(@equipment.last_checked_at)}

priv/repo/migrations/20260105134321_fix_sensor_readings_primary_key.exs

@@ -0,0 +1,49 @@
+defmodule Towerops.Repo.Migrations.FixSensorReadingsPrimaryKey do
+  use Ecto.Migration
+
+  def up do
+    # Drop and recreate the table with correct primary key type
+    # This is safe because sensor readings are time-series data that regenerates
+    drop table(:snmp_sensor_readings)
+
+    create table(:snmp_sensor_readings, primary_key: false) do
+      add :id, :binary_id, primary_key: true
+
+      add :sensor_id, references(:snmp_sensors, type: :binary_id, on_delete: :delete_all),
+        null: false
+
+      add :value, :float
+      add :status, :string, null: false
+      add :checked_at, :utc_datetime, null: false
+
+      timestamps(type: :utc_datetime, updated_at: false)
+    end
+
+    # Recreate indexes
+    create index(:snmp_sensor_readings, [:sensor_id])
+    create index(:snmp_sensor_readings, [:sensor_id, :checked_at])
+    create index(:snmp_sensor_readings, [:status])
+    create index(:snmp_sensor_readings, [:checked_at])
+  end
+
+  def down do
+    # Recreate with old integer primary key
+    drop table(:snmp_sensor_readings)
+
+    create table(:snmp_sensor_readings) do
+      add :sensor_id, references(:snmp_sensors, type: :binary_id, on_delete: :delete_all),
+        null: false
+
+      add :value, :float
+      add :status, :string, null: false
+      add :checked_at, :utc_datetime, null: false
+
+      timestamps(type: :utc_datetime, updated_at: false)
+    end
+
+    create index(:snmp_sensor_readings, [:sensor_id])
+    create index(:snmp_sensor_readings, [:sensor_id, :checked_at])
+    create index(:snmp_sensor_readings, [:status])
+    create index(:snmp_sensor_readings, [:checked_at])
+  end
+end

priv/repo/migrations/20260105134404_fix_interface_stats_primary_key.exs

@@ -0,0 +1,55 @@
+defmodule Towerops.Repo.Migrations.FixInterfaceStatsPrimaryKey do
+  use Ecto.Migration
+
+  def up do
+    # Drop and recreate the table with correct primary key type
+    # This is safe because interface stats are time-series data that regenerates
+    drop table(:snmp_interface_stats)
+
+    create table(:snmp_interface_stats, primary_key: false) do
+      add :id, :binary_id, primary_key: true
+
+      add :interface_id, references(:snmp_interfaces, type: :binary_id, on_delete: :delete_all),
+        null: false
+
+      add :if_in_octets, :bigint
+      add :if_out_octets, :bigint
+      add :if_in_errors, :bigint
+      add :if_out_errors, :bigint
+      add :if_in_discards, :bigint
+      add :if_out_discards, :bigint
+      add :checked_at, :utc_datetime, null: false
+
+      timestamps(type: :utc_datetime, updated_at: false)
+    end
+
+    # Recreate indexes
+    create index(:snmp_interface_stats, [:interface_id])
+    create index(:snmp_interface_stats, [:interface_id, :checked_at])
+    create index(:snmp_interface_stats, [:checked_at])
+  end
+
+  def down do
+    # Recreate with old integer primary key
+    drop table(:snmp_interface_stats)
+
+    create table(:snmp_interface_stats) do
+      add :interface_id, references(:snmp_interfaces, type: :binary_id, on_delete: :delete_all),
+        null: false
+
+      add :if_in_octets, :bigint
+      add :if_out_octets, :bigint
+      add :if_in_errors, :bigint
+      add :if_out_errors, :bigint
+      add :if_in_discards, :bigint
+      add :if_out_discards, :bigint
+      add :checked_at, :utc_datetime, null: false
+
+      timestamps(type: :utc_datetime, updated_at: false)
+    end
+
+    create index(:snmp_interface_stats, [:interface_id])
+    create index(:snmp_interface_stats, [:interface_id, :checked_at])
+    create index(:snmp_interface_stats, [:checked_at])
+  end
+end

priv/repo/migrations/20260105142046_fix_monitoring_checks_primary_key.exs

@@ -0,0 +1,46 @@
+defmodule Towerops.Repo.Migrations.FixMonitoringChecksPrimaryKey do
+  use Ecto.Migration
+
+  def up do
+    # Drop and recreate the table with correct primary key type
+    drop table(:monitoring_checks)
+
+    create table(:monitoring_checks, primary_key: false) do
+      add :id, :binary_id, primary_key: true
+
+      add :equipment_id, references(:equipment, type: :binary_id, on_delete: :delete_all),
+        null: false
+
+      add :status, :string, null: false
+      add :response_time_ms, :integer
+      add :checked_at, :utc_datetime, null: false
+
+      timestamps(type: :utc_datetime, updated_at: false)
+    end
+
+    # Recreate indexes
+    create index(:monitoring_checks, [:equipment_id])
+    create index(:monitoring_checks, [:equipment_id, :checked_at])
+    create index(:monitoring_checks, [:checked_at])
+  end
+
+  def down do
+    # Recreate with old integer primary key
+    drop table(:monitoring_checks)
+
+    create table(:monitoring_checks) do
+      add :equipment_id, references(:equipment, type: :binary_id, on_delete: :delete_all),
+        null: false
+
+      add :status, :string, null: false
+      add :response_time_ms, :integer
+      add :checked_at, :utc_datetime, null: false
+
+      timestamps(type: :utc_datetime, updated_at: false)
+    end
+
+    create index(:monitoring_checks, [:equipment_id])
+    create index(:monitoring_checks, [:equipment_id, :checked_at])
+    create index(:monitoring_checks, [:checked_at])
+  end
+end