import { Command as $Command } from "@aws-sdk/smithy-client";
import { Handler, HttpHandlerOptions as __HttpHandlerOptions, MetadataBearer as __MetadataBearer, MiddlewareStack } from "@aws-sdk/types";
import { EC2ClientResolvedConfig, ServiceInputTypes, ServiceOutputTypes } from "../EC2Client";
import { DescribeInstancesRequest, DescribeInstancesResult } from "../models/models_3";
export interface DescribeInstancesCommandInput extends DescribeInstancesRequest {
}
export interface DescribeInstancesCommandOutput extends DescribeInstancesResult, __MetadataBearer {
}
/**
 * <p>Describes the specified instances or all instances.</p>
 *         <p>If you specify instance IDs, the output includes information for only the specified
 *             instances. If you specify filters, the output includes information for only those
 *             instances that meet the filter criteria. If you do not specify instance IDs or filters,
 *             the output includes information for all instances, which can affect performance. We
 *             recommend that you use pagination to ensure that the operation returns quickly and
 *             successfully.</p>
 *         <p>If you specify an instance ID that is not valid, an error is returned. If you specify
 *             an instance that you do not own, it is not included in the output.</p>
 *         <p>Recently terminated instances might appear in the returned results. This interval is
 *             usually less than one hour.</p>
 *         <p>If you describe instances in the rare case where an Availability Zone is experiencing
 *             a service disruption and you specify instance IDs that are in the affected zone, or do
 *             not specify any instance IDs at all, the call fails. If you describe instances and
 *             specify only instance IDs that are in an unaffected zone, the call works
 *             normally.</p>
 *         <note>
 *             <p>We are retiring EC2-Classic on August 15, 2022. We recommend that you migrate from EC2-Classic to a VPC. For more information, see <a href="https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/vpc-migrate.html">Migrate from EC2-Classic to a VPC</a> in the <i>Amazon EC2 User Guide</i>.</p>
 *         </note>
 * @example
 * Use a bare-bones client and the command you need to make an API call.
 * ```javascript
 * import { EC2Client, DescribeInstancesCommand } from "@aws-sdk/client-ec2"; // ES Modules import
 * // const { EC2Client, DescribeInstancesCommand } = require("@aws-sdk/client-ec2"); // CommonJS import
 * const client = new EC2Client(config);
 * const command = new DescribeInstancesCommand(input);
 * const response = await client.send(command);
 * ```
 *
 * @see {@link DescribeInstancesCommandInput} for command's `input` shape.
 * @see {@link DescribeInstancesCommandOutput} for command's `response` shape.
 * @see {@link EC2ClientResolvedConfig | config} for EC2Client's `config` shape.
 *
 */
export declare class DescribeInstancesCommand extends $Command<DescribeInstancesCommandInput, DescribeInstancesCommandOutput, EC2ClientResolvedConfig> {
    readonly input: DescribeInstancesCommandInput;
    constructor(input: DescribeInstancesCommandInput);
    /**
     * @internal
     */
    resolveMiddleware(clientStack: MiddlewareStack<ServiceInputTypes, ServiceOutputTypes>, configuration: EC2ClientResolvedConfig, options?: __HttpHandlerOptions): Handler<DescribeInstancesCommandInput, DescribeInstancesCommandOutput>;
    private serialize;
    private deserialize;
}
