[vog/systemlag] Voq lagid allocator

orchagent/lagid.cpp

@@ -0,0 +1,96 @@
+#include "lagid.h"
+
+LagIdAllocator::LagIdAllocator(
+        _In_ DBConnector* chassis_app_db)
+{
+    SWSS_LOG_ENTER();
+
+    m_dbConnector = chassis_app_db;
+
+    // Load lua script to allocate system lag id. This lua script ensures allocation
+    // of unique system lag id from global chassis app db in atomic fashion when allocation
+    // is requested by different asic instances simultaneously
+
+    string luaScript = loadLuaScript("lagids.lua");
+    m_shaLagId = loadRedisScript(m_dbConnector, luaScript);
+}
+
+int32_t LagIdAllocator::lagIdAdd(
+        _In_ const string &pcname,
+        _In_ int32_t lag_id)
+{
+    SWSS_LOG_ENTER();
+
+    // No keys
+    vector<string> keys;
+
+    vector<string> args;
+    args.push_back("add");
+    args.push_back(pcname);
+    args.push_back(to_string(lag_id));
+
+    set<string> ret = runRedisScript(*m_dbConnector, m_shaLagId, keys, args);
+
+    if (!ret.empty())
+    {
+        // We expect only one value in the set returned
+
+        auto rv_lag_id = ret.begin();
+
+        return (stoi(*rv_lag_id));
+    }
+
+    return LAG_ID_ALLOCATOR_ERROR_DB_ERROR;
+}
+
+int32_t LagIdAllocator::lagIdDel(
+        _In_ const string &pcname)
+{
+    SWSS_LOG_ENTER();
+
+    // No keys
+    vector<string> keys;
+
+    vector<string> args;
+    args.push_back("del");
+    args.push_back(pcname);
+
+    set<string> ret = runRedisScript(*m_dbConnector, m_shaLagId, keys, args);
+
+    if (!ret.empty())
+    {
+        // We expect only one value in the set returned
+
+        auto rv_lag_id = ret.begin();
+
+        return (stoi(*rv_lag_id));
+    }
+
+    return LAG_ID_ALLOCATOR_ERROR_DB_ERROR;
+}
+
+int32_t LagIdAllocator::lagIdGet(
+        _In_ const string &pcname)
+{
+    SWSS_LOG_ENTER();
+
+    // No keys
+    vector<string> keys;
+
+    vector<string> args;
+    args.push_back("get");
+    args.push_back(pcname);
+
+    set<string> ret = runRedisScript(*m_dbConnector, m_shaLagId, keys, args);
+
+    if (!ret.empty())
+    {
+        // We expect only one value in the set returned
+
+        auto rv_lag_id = ret.begin();
+
+        return (stoi(*rv_lag_id));
+    }
+
+    return LAG_ID_ALLOCATOR_ERROR_DB_ERROR;
+}

orchagent/lagid.h

@@ -0,0 +1,44 @@
+#ifndef SWSS_LAGID_H
+#define SWSS_LAGID_H
+
+#include "dbconnector.h"
+#include "sal.h"
+#include "schema.h"
+#include "redisapi.h"
+
+using namespace swss;
+using namespace std;
+
+#define LAG_ID_ALLOCATOR_ERROR_DELETE_ENTRY_NOT_FOUND  0
+#define LAG_ID_ALLOCATOR_ERROR_TABLE_FULL             -1
+#define LAG_ID_ALLOCATOR_ERROR_GET_ENTRY_NOT_FOUND    -2
+#define LAG_ID_ALLOCATOR_ERROR_INVALID_OP             -3
+#define LAG_ID_ALLOCATOR_ERROR_DB_ERROR               -4
+
+class LagIdAllocator
+{
+public:
+
+    LagIdAllocator(
+            _In_ DBConnector* chassis_app_db);
+
+public:
+
+    int32_t lagIdAdd(
+            _In_ const string &pcname,
+            _In_ int32_t lag_id);
+
+    int32_t lagIdDel(
+            _In_ const string &pcname);
+
+    int32_t lagIdGet(
+            _In_ const string &pcname);
+
+private:
+
+    DBConnector* m_dbConnector;
+
+    string m_shaLagId;
+};
+
+#endif // SWSS_LAGID_H

orchagent/lagids.lua

@@ -0,0 +1,88 @@
+-- KEYS - None
+-- ARGV[1] - operation (add/del/get)
+-- ARGV[2] - lag name
+-- ARGV[3] - current lag id (for "add" operation only)
+
+-- return lagid if success for "add"/"del"
+-- return 0 if lag does not exist for "del"
+-- return -1 if lag table full for "add"
+-- return -2 if lag does not exist for "get"
+-- return -3 if invalid operation
+
+local op = ARGV[1]
+local pcname = ARGV[2]
+
+local lagid_start = tonumber(redis.call("get", "SYSTEM_LAG_ID_START"))
+local lagid_end = tonumber(redis.call("get", "SYSTEM_LAG_ID_END"))
+
+if op == "add" then
+
+    local plagid = tonumber(ARGV[3])
+
+    local dblagid = redis.call("hget", "SYSTEM_LAG_ID_TABLE", pcname)
+
+    if dblagid then
+        dblagid = tonumber(dblagid)
+        if plagid == 0 then
+            -- no lagid proposed. Return the existing lagid
+            return dblagid
+        end
+    end
+
+    -- lagid allocation request with a lagid proposal
+    if plagid >= lagid_start and plagid <= lagid_end then
+        if plagid == dblagid then
+            -- proposed lagid is same as the lagid in database
+            return plagid
+        end
+        -- proposed lag id is different than that in database OR
+        -- the portchannel does not exist in the database
+        -- If proposed lagid is available, return the same proposed lag id
+        if redis.call("sismember", "SYSTEM_LAG_ID_SET", tostring(plagid)) == 0 then
+            redis.call("sadd", "SYSTEM_LAG_ID_SET", tostring(plagid))
+            redis.call("srem", "SYSTEM_LAG_ID_SET", tostring(dblagid))
+            redis.call("hset", "SYSTEM_LAG_ID_TABLE", pcname, tostring(plagid))
+            return plagid
+        end
+    end
+
+    local lagid = lagid_start
+    while lagid <= lagid_end do
+        if redis.call("sismember", "SYSTEM_LAG_ID_SET", tostring(lagid)) == 0 then
+            redis.call("sadd", "SYSTEM_LAG_ID_SET", tostring(lagid))
+            redis.call("srem", "SYSTEM_LAG_ID_SET", tostring(dblagid))
+            redis.call("hset", "SYSTEM_LAG_ID_TABLE", pcname, tostring(lagid))
+            return lagid
+        end
+        lagid = lagid + 1
+    end
+
+    return -1
+
+end
+
+if op == "del" then
+
+    if redis.call("hexists", "SYSTEM_LAG_ID_TABLE", pcname) == 1 then
+        local lagid = redis.call("hget", "SYSTEM_LAG_ID_TABLE", pcname)
+        redis.call("srem", "SYSTEM_LAG_ID_SET", lagid)
+        redis.call("hdel", "SYSTEM_LAG_ID_TABLE", pcname)
+        return tonumber(lagid)
+    end
+
+    return 0
+
+end
+
+if op == "get" then
+
+    if redis.call("hexists", "SYSTEM_LAG_ID_TABLE", pcname) == 1 then
+        local lagid = redis.call("hget", "SYSTEM_LAG_ID_TABLE", pcname)
+        return tonumber(lagid)
+    end
+
+    return -2
+
+end
+
+return -3